This opinion will be unpublished and
may not be cited except as provided by
Minn. Stat. § 480A.08, subd. 3 (2004).
IN COURT OF APPEALS
Affirmed in part and reversed in part
Hennepin County District Court
File No. CT9816270
Vincent D. Louwagie, Mark D. Wisser, Anthony Ostlund & Baer, P.A., Suite 3600, 90 South Seventh Street, Minneapolis, MN 55402 (for appellants Nessi and Watson)
John F. Beukema, Faegre & Benson, L.L.P., 2200 Wells Fargo Center, 90 South Seventh Street, Minneapolis, MN 55402 (for respondent Sudovest Group, Inc.)
Considered and decided by Lansing, Presiding Judge; Willis, Judge; and Stoneburner, Judge.
In this consolidated appeal, Sergio Nessi (A04-1465) and Kathleen Ellen Watson (A04-1461) challenge the district court’s judgment allowing respondent Sudovest Group, Inc. to rescind a contract with Nessi and setting off the judgment for rescission against a judgment previously awarded to Nessi on his claim against Sudovest on an unrelated promissory note. We affirm in part and reverse in part.
In 1997, Sergio Nessi entered into a written security agreement with Kathleen Watson giving Watson a security interest in a note issued by Sudovest Group, Inc., as payor, to Nessi as payee (Sudovest note), to secure payment of a loan Watson made to Gato, LLC, a company owned by members of the Nessi family. Under the terms of the security agreement, Watson took possession of the note to perfect her security interest. Watson remained in possession of the note at all relevant times.
In August 1998, Nessi sued Sudovest on the Sudovest note. Sudovest counterclaimed, asserting a claim of its principal, Antonio Percassi, to rescind an unrelated 1995 contract between Percassi and Nessi. Percassi had assigned his rescission claim, which was based on unilateral mistake, to Sudovest shortly before Sudovest’s answer to Nessi’s action on the Sudovest note was due.
After a bench trial, the district court entered judgment in favor of Sergio Nessi on the Sudovest note and dismissed Sudovest’s counterclaim on the basis that Minnesota law does not allow rescission of a contract based on unilateral mistake in the absence of fraud or other wrongful conduct on the part of the non-mistaken party. Judgment was originally entered on July 30, 2001, and an amended judgment was entered on September 12, 2001. Sudovest appealed dismissal of the counterclaim but did not appeal judgment for Nessi on the Sudovest note.
Gato defaulted on its note to Watson. Watson foreclosed on the Sudovest note and bought it at a public sale on March 29, 2002, for the amount Gato owed her. A document titled “Assignment of Promissory Note After Sale by Secured Party” gave Watson “all of the right, title and interest of Sergio Nessi” to the Sudovest note. Three days later, Watson intervened in Nessi’s action against Sudovest to assert her interest in Nessi’s judgment on the note. Watson’s intervention occurred while Sudovest’s appeal on the counterclaim was pending. This court reversed the district court’s dismissal of Sudovest’s counterclaim for rescission of the 1995 contract between Nessi and Percassi, and remanded for application of Italian law, which permits rescission based on unilateral mistake, to the rescission claim. Nessi v. Sudovest Group, Inc., 2002 WL 1751210, *2 (Minn. App.).
When the file was returned from this court to the district court for reconsideration of Sudovest’s counterclaim, the district court administrator vacated the judgment that had been entered, including judgment in favor of Sergio Nessi on the Sudovest note from which no appeal was taken. The vacation of judgment occurred on September 26, 2002, almost six months after Watson had intervened and asserted her interest in the judgment on the Sudovest note. Watson moved to reinstate the judgment. The motion was denied. Watson then moved to be substituted as plaintiff for Sergio Nessi on the ground that, under the UCC, she owned the judgment as “proceeds” of the note. That motion was denied.
On remand, the district court applied Italian law to the finding it had made in the initial trial on the counterclaim that Percassi entered into the July 1995 contract with Sergio Nessi in the mistaken belief that he was required to repay a May 1992 loan from Sergio Nessi to Percassi, because Percassi had forgotten about a “scrittura privata” that excused repayment unless specific conditions were met. The district court found that under Italian law, Percassi’s mistake was both “essential” to the July 1995 contract and “recognizable” within the meaning of the Italian Civil Code, that Nessi knew in October 1994 and July 1995 that the scrittura privata excused Percassi from repaying the May 1992 loan unless specified conditions were met, and that Nessi knew on those dates that the conditions had not been met. The court also found that a reasonable person in Nessi’s position would have known in July 1995 that Percassi was mistaken about his obligation to repay the May 1992 loan when the parties entered into the July 1995 contract.
Based on these findings, the district court concluded that Sudovest, as the assignee of Percassi’s rights, was entitled to rescind the July 1995 contract and recover from Nessi 900 million lire that Percassi mistakenly paid under the July 1995 contract.
The district court did not address Nessi’s argument, asserted on remand, that Sudovest lacked standing to seek rescission of this contract, depriving the court of subject-matter jurisdiction. The district court set off the judgment on the Sudovest note against the damages for rescission, resulting in a net judgment for Sudovest. Appeals by Nessi and Watson followed and were consolidated.
On appeal, Nessi and Watson both assert that the district court lacked subject-matter jurisdiction over Sudovest’s counterclaim for rescission of the 1995 contract between Nessi and Percassi. Nessi also asserts that the district court erred in its interpretation of Italian law. Watson asserts that the district court erred in vacating the judgment to Nessi on the Sudovest note from which no appeal was taken, misapplied the UCC in concluding that Watson does not own the judgment obtained by Nessi, abused its discretion by denying her motion to be substituted as plaintiff for Sergio Nessi, and erred by allowing Sudovest to offset its counterclaim against a judgment she asserts she owned.
The parties agree that Minnesota law controls the issue of whether the district court had jurisdiction over Sudovest’s counterclaim for rescission of the July 1995 contract between Nessi and Percassi. Subject matter jurisdiction is a question of law reviewed de novo. Johnson v. Murray, 648 N.W.2d 664, 670 (Minn. 2002). The issue of subject-matter jurisdiction can be raised at any time. Minn. R. Civ. P. 12.08(c).
A genuine conflict in the interests of opposing litigants is not enough to create jurisdiction; a litigant must also have standing. State by Humphrey v. Philip Morris, Inc., 551 N.W.2d 490, 493 (Minn. 1996). A litigant has standing when the litigant has suffered an actual injury or otherwise has a sufficient stake in a justiciable controversy to seek relief from a court. Cochrane v. Tutor Oaks Condominium Project, 529 N.W.2d 429, 433 (Minn. App. 1995), review denied (Minn. May 31, 1995). Standing is jurisdictional because it goes to the existence of a justiciable controversy. Kilpatrick v. Kilpatrick, 673 N.W.2d 528, 530 (Minn. App. 2004).
“A valid assignment generally operates to vest in the assignee the same right, title or interest that the assignor had in the thing assigned.” State ex rel. Southwell v. Chamberland, 361 N.W.2d 814, 818 (Minn. 1985). “In effect, an assignee stands in the shoes of the assignor.” Geldert v. Am. Nat’l Bank, 506 N.W.2d 22, 29 (Minn. App. 1993), review denied (Minn. Nov. 16, 1993). At common law, “ordinary causes of action were not assignable.” Peterson v. Brown, 457 N.W.2d 745, 748 (Minn. App. 1990), review denied (Minn. Aug. 23, 1990). The rule prohibiting assignment of a cause of action “was grounded on public policy considerations relating to champerty and maintenance.” Id. (citing Travelers Indem. Co. v. Vaccari, 310 Minn. 97, 100-101, 245 N.W.2d 844, 846 (1976). But this “flat prohibition . . . conflicted with emerging commercial interests and in most states the common law was modified to provide that actions that survive the death of the holder may be assigned.” Id. This is the rule in Minnesota. Id.; see Leuthold v. Redwood County, 206 Minn. 199, 201, 288 N.W. 165, 166 (1939) (stating the test of assignability of a claim generally is whether a cause of action survives to the personal representative of a decedent). Minn. Stat. § 573.01 (2004), provides that, except for actions arising out of an injury to the person, all other causes of action survive the death of the holder.
Notwithstanding the general assignability of contract claims, appellants assert that under Minnesota law, a bare right of rescission is not assignable, citing dictum from Norwest Fin. Leasing, Inc. v. Morgan Whitney, Inc., 787 F.Supp. 895, 899-900 (D. Minn. 1992). Because Percassi assigned only his right to rescind the July 1995 contract, appellants argue that the assignment was invalid and did not give Sudovest standing to assert the claim.
Norwest Fin. Leasing cited Cornell v. Upper Michigan Land Co., 131 Minn. 337, 155 N.W. 99 (1915) for the proposition that a right of rescission is not assignable. In Cornell, the supreme courtacknowledged the “rule that an assignment of a bare right to file a bill in equity for fraud committed upon the assignor is void as against public policy and savoring of the character of maintenance[.]” Id. at 344, 155 N.W.2d at 102. But because the entire contracts involved in Cornell had been assigned, the supreme court held that the rule was inapplicable. Id. at 344, 155 N.W.2d at 102. We can find no other cases in Minnesota or elsewhere dealing with “assignment of a bare right to file a bill in equity,” and no cases specifically modifying, applying or negating the “rule” acknowledged in Cornell. “Maintenance” is defined as “assistance in prosecuting or defending a lawsuit given to a litigant by someone who has no bona fide interest in the case; meddling in someone else’s litigation.” Black’s Law Dictionary 965 (7th ed. 1999). In this case, Percassi, as principal of Sudovest, has a bona fide interest in the outcome of litigation against Sudovest. Appellants argue that Sudovest has not suffered an injury-in-fact in connection with the 1995 contract between Percassi and Nessi and therefore should not have standing to assert Percassi’s claim, but this argument misses the point that Sudovest does not assert standing based on an injury-in-fact to Sudovest but asserts standing based on an assignment under which it steps into Percassi’s shoes.
Appellants have not articulated any currently recognized policy reasons for applying the common-law rule recognized in Cornell to this case. Here, Percassi had performed his obligations under the 1995 contract and there does not appear to be any other right or duty arising out of the contract, other than the rescission claim, that he could have assigned to Sudovest. Appellants make much of the fact that 11 months before Nessi brought suit against Sudovest in Minnesota, he sued Percassi in Italy to collect interest under the 1995 contract, and Percassi failed to assert his rescission claim in that action which apparently was not concluded until 2003. But Percassi assigned the rescission claim to Sudovest soon after he discovered he had such a claim, and we are not persuaded that Percassi’s defense of the suit in Italy invalidated the assignment of the rescission claim. Despite the apparent existence of a rule in 1915 that precluded the assignment of a bare-rescission claim as against public policy and savoring of maintenance, we do not find sufficient authority to impose such a rule to preclude Sudovest’s standing in this case to assert Percassi’s rescission claim. The district court did not err by implicitly denying appellants’ claim that the court lacked subject-matter jurisdiction over Sudovest’s counterclaim.
II. Application of Italian law
a. Evidence supports the court’s finding that Percassi’s mistake was essential to the July 1995 contract
Nessi asserts that the district court’s findings about Italian law are clearly erroneous as well as arbitrary and capricious. Foreign law is a question of fact that must be proved like any other fact. Greear v. Paust, 202 Minn. 633, 636, 279 N.W. 568, 570 (Minn. 1938) (stating that a law of a foreign country is a matter of fact which the courts cannot be presumed to be acquainted with or to take judicial notice of unless it is pleaded and proved). “Findings of fact, whether based on oral or documentary evidence, shall not be set aside unless clearly erroneous, and due regard shall be given to the opportunity of the trial court to judge the credibility of the witnesses.” Minn. R. Civ. P. 52.01. Findings of fact are clearly erroneous when they are not “reasonably supported by evidence in the record considered as a whole.” Hubbard v. United Press Int’l, Inc., 330 N.W.2d 428, 441 (Minn. 1983).
Italian law allows for rescission of a contract based on a unilateral mistake that is “essential” and “recognizable” by the other party. Italian Civil Code § 1428. A mistake is essential when it relates to the object of an agreement. Id. Nessi argues that the condition of repayment contained in the scrittura privata remained a condition at the time of the July 1995 agreement “and, accordingly, had not become an object of any contract.” The district court rejected Nessi’s proffered definition of “object” as only the tangible material that changes hands in a contract.
From our review of the record, we conclude that there is sufficient evidence in Sudovest’s expert’s affidavits and deposition testimony to support the district court’s finding that Percassi’s mistaken belief that he was unconditionally obligated to repay the May 1992 loan was essential to the July 1995 contract. Because the evidence supports this finding, it is not clearly erroneous.
b. Evidence supports the finding that the condition was not satisfied
Article 1359 of the Italian Civil Code provides that “a condition is considered fulfilled when it fails for a cause imputable to the party who had an interest contrary to its fulfillment.” Based on this provision, Nessi argues that the condition on which Percassi’s repayment obligation was based was fulfilled as a matter of law when Percassi gained control over the corporations that had the power to fulfill the condition. Although not articulated, the argument appears to be that, therefore, in July 1995, Percassi’s repayment obligation was absolute so there could be no mistake on his part. But the district court found in its original order that Percassi entered into the 1995 loan agreement under a mistaken belief. And there is no evidence in the record that Percassi caused the condition not to be fulfilled but there is evidence in the record that no funds were available from the corporations controlled by Percassi to meet the condition. The district court did not err by failing to impute nonfulfillment of the condition to Percassi.
c. Sudovest met its burden of proof that Italian law supports rescission
Nessi argues that Sudovest failed to meet its burden of proving by a preponderance of the evidence that Sudovest’s view of Italian contract law is correct. Nessi bases this argument on his assertion that Sudovest’s Italian law expert was not an expert and was not credible.
When reviewing a district court ruling on the competence of a proffered expert witness, the appellate court must apply a deferential standard reversing only if there is an abuse of discretion, and may not conduct an independent review of the credentials of the witness. Gross v. Victoria Station Farms, Inc., 578 N.W.2d 757, 761 (Minn. 1998). And it is well-settled that judging the credibility of witnesses and the weight given to their testimony rests within the province of the finder of fact. General v. General, 409 N.W.2d 511, 513 (Minn. App. 1987). On the record before us, we cannot say that the district court abused its discretion by relying on Sudovest’s expert’s explanation of Italian law, therefore, we find this argument without merit.
d. Judicial estoppel
Nessi asserts that there is a direct contradiction between assertions made by Percassi and Sudovest here and in legal proceedings in Italy on the July 1995 contract.
Judicial estoppel prevents a party that has taken one position in litigating a particular set of facts from later reversing its position when it is to its advantage to do so. It is intended to protect the courts from being manipulated by chameleonic litigants who seek to prevail, twice, on opposite theories.
Bauer v. Blackduck Ambulance Ass’n, 614 N.W.2d 747, 749-50 (Minn. App. 2000). Because the facts and issues in these actions were not the same, we find this argument without merit.
When this court reversed the district court’s dismissal of Sudovest’s counterclaim and remanded that issue to the district court for application of Italian law, the district court administrator vacated the September 12, 2001 judgment despite the fact that judgment for Nessi on the Sudovest note had become final when Sudovest failed to appeal from that judgment. Watson immediately moved to reinstate the judgment for Nessi on the Sudovest note so that she could pursue her claim for that judgment as proceeds of the Sudovest note, which she then owned and in which she previously had a perfected-security interest. Watson argued that vacation of the judgment in favor of Nessi on the Sudovest note was a clerical mistake correctible by the court under Minn. R. Civ. P. 60.01. Watson argued that although not directly applicable, the principle underlying Minn. R. Civ. P. 54.02, which permits a court to enter partial judgment, applies to permit vacation of only the portion of the judgment reversed by this court.
Sudovest opposed the motion. Sudovest conceded that the judgment for Nessi on the Sudovest note was final and conclusive and had to be reinstated eventually, but argued that Watson did not have any greater interest in the judgment than Sudovest’s interest in a potential setoff if Sudovest succeeded on its counterclaim.
The district court denied Watson’s motion, noting that its authority to enter partial judgment under Minn. R. Civ. P. 54.02 is discretionary, and essentially determining that even if the district court had discretion to reinstate the judgment for Nessi, Sudovest’s potential right to a setoff had priority over any claim Watson had to the judgment.
We conclude that the district court’s reasoning and conclusion is flawed by its failure to recognize Watson’s security interest in the judgment on the Sudovest note, which, we conclude, gave her priority over any claim Sudovest had to that judgment.
IV. Watson’s interest in the promissory note and judgment
The parties agree that Arizona law applies to Watson’s rights with regard to the Sudovest note. Statutory construction and the application of a statute to undisputed facts presents a question of law, which this court reviews de novo without being bound by the district court’s decision. Dachtera v. Whitehouse, 609 N.W.2d 248, 249 (Minn. App. 2000).
In the district court, Watson, without abandoning any of her rights to the judgment on the Sudovest note as a secured party, also asserted that she had a right to enforce the Sudovest note as a holder, or transferee with rights of a holder. On appeal, she concedes she was not a holder, but she continues to assert that she had a right to enforce the note as a transferee.
Ariz. Rev. Stat. § 47-3203(A) (2004), provides that “[a]n instrument is transferred when it is delivered by a person other than its issuer for the purpose of giving to the person receiving delivery the right to enforce the instrument.” Comment 1 to Ariz. Rev. Stat. § 47-3203, states that cases in which possession of an instrument is delivered for some purpose other than transfer of the right to enforce it are excluded from the transfer provision. Here, the security agreement under which Watson obtained possession of the Sudovest note specifically provides that Watson’s taking possession of the Sudovest note is for the purpose of perfecting her security interest in the note. The security agreement further provides that in the event of a default, Watson “shall have remedies as a secured party under the Uniform Commercial Code, as adopted in the State of Arizona.”
The remedies of a secured party include a right to proceeds of the collateral under Ariz. Rev. Stat. § 47-9315 (2004), and rights after default under Ariz. Rev. Stat. § 47-9601 (2004). We conclude that transfer of the Sudovest note to Watson was for a purpose other than to enforce the instrument and that she is not a transferee under the provisions of the UCC.
Nonetheless, Watson was a secured party. She foreclosed on the Sudovest note and, by reason of purchasing the Sudovest note at a public sale, obtained all of Nessi’s interest in the Sudovest note as of March 29, 2002. Even if Nessi did not have any
interest in the Sudovest note on that date because the note had merged into the judgment, Watson asserts that, as owner of Nessi’s rights in the Sudovest note, she automatically became owner of the proceeds of the note. It is undisputed that the judgment constitutes proceeds of the Sudovest note. Although this is a logical conclusion, Watson has not provided, nor can we find, any authority to support it. But there is authority to support Watson’s claim to the judgment as proceeds of the Sudovest note due to her status as a secured party. Remedies of a secured party under the UCC are cumulative and can be pursued simultaneously, and Watson’s interest in the judgment in light of her perfected security interest in the Sudovest note leads us to conclude that her claim to the judgment had priority over any potential claim Sudovest had for a setoff of that judgment against its potential judgment on its counterclaim.
Under the UCC, because her security interest in the note was perfected, Watson obtained an automatic perfected security interest in the proceeds of the Sudovest note. Ariz. Rev. Stat. § 47-9304(C). Watson’s perfected security interest in the judgment, however, appears to have become unperfected on the 21st day after it attached. Ariz. Rev. Stat. § 47- 9315(D). But she still had an unperfected security interest in the proceeds and Sudovest did not have a lien, security interest, or any other identifiable claim to the proceeds of the note, other than a potential claim for setoff if it eventually succeeded on its counterclaim. There is no provision of Article 9 of the UCC that subordinates Watson’s claim to the claim advanced by Sudovest.
Sudovest asserts that it is an account debtor to Nessi and therefore is entitled to priority over Watson’s claim under Ariz. Rev. Stat. § 47-9404(A), which provides:
Unless an account debtor has made an enforceable agreement not to assert defenses or claims, and subject to subsections (B) through (E), the rights of an assignee are subject to:
. . . .
(2) any other defense or claim of the account debtor against the assignor that accrues before the account debtor receives a notification of the assignment authenticated by the assignor or the assignee.
Article 9 defines “account debtor” as “a person obligated on an account, chattel paper or general intangible but does not include persons obligated to pay a negotiable instrument, even if the instrument constitutes part of chattel paper.” Ariz. Stat. § 47-9102(A)(3) (2004). When the assignment to Watson of a perfected security interest in the Sudovest note occurred, Sudovest was “a person obligated to pay a negotiable instrument” (the Sudovest note) and was, therefore, not an “account debtor” under the plain language of the statute.
Sudovest seems to assert that Watson took her security interest subject to Sudovest’s counterclaim because Sudovest became an account debtor once it became obligated to pay a judgment on the Sudovest note. Sudovest has provided no authority to support its claim that a judgment debtor is an account debtor other than to assert that a judgment on a claim is a “payment intangible.” A “payment intangible” is defined as a “general intangible under which the account debtor's principal obligation is a monetary obligation.” Ariz. Rev. Stat. § 47-9102(61)(2004). It may be that a judgment would fit into this category, but that fact would not help Sudovest. Sudovest may not use its newfound status as an “account debtor” to reach back in time to the point when the assignment to Watson was made. Nessi assigned a security interest in the Sudovest note to Watson long before Sudovest became an account debtor, when Sudovest was simply an obligor on the Sudovest note.
Sudovest has not presented any authority to support its claim that its rights to setoff its judgment on an unrelated counterclaim is superior to Watson’s security interest in the judgment. Ariz. Stat. § 47-9201A (2004), provides that “a security agreement is effective . . . against creditors.” The fact that Sudovest became a creditor of Nessi when it succeeded on its counterclaim does not defeat Watson’s security interest in the judgment on the Sudovest note.
Because Watson, as a secured party, had priority over any claim Sudovest asserted to the proceeds of the Sudovest note, we conclude that the district court erred by failing to reinstate the judgment for Nessi that was vacated by the court administrator, and erred in setting off that judgment against Sudovest’s later-granted judgment on its unrelated counterclaim. Because we reverse denial of Watson’s motion to reinstate the judgment and we reverse the setoff, it is unnecessary to address Watson’s claim that the district court erred by denying her motion to be substituted as a party for Nessi.
Affirmed in part and reversed in part.
 Under the scrittura privata, Percassi did not have to repay Nessi 900 million lire if proof was not supplied by a specified date that Percassi had been paid a like amount by specified companies.
 Sudovest’s expert discussed at length a treatise by V. Pietrobon, “L’Errore nella dottrina del negozio giuridico” which is cited as the only authority in annotations to Art. 1429 of the Italian Civil Code found in Commentario Breve al Codice Civile, recognized by both parties as a detailed collection of authorities and case law on the Italian Civil Code. The expert explains that
[a] mistake on the object of the contract consists, therefore . . . of a mistake on the conflict of interest that the parties intend to regulate with the contract . . . [T]he mistake on the object consists, in substance, of an incorrect understanding that has caused a person to believe in the existence of a conflict of interest that in fact did not have any reason to exist.
 The district court stated,
If successful, Sudovest’s remanded counterclaim will reduce the amount that Sudovest has been held to owe to [Nessi] on the promissory note. If this occurs, then [Nessi], and by extension, Watson, will be entitled to enforce only the net amount of the single resulting judgment . . . offset may realistically be the only means by which Sudovest could obtain the benefit of winning a counterclaim . . . the harm that Watson will incur as a result of the denial of her motion does not, at this point, seem substantial[.]
 Arizona and Minnesota law are identical in all provisions relating to the Uniform Commercial Code that are relevant to this case.
 And, at the time the Sudovest note was given to Watson, the only way a secured party could perfect its security interest in a promissory note was by taking possession. Ariz. Rev. Stat. § 47-9304(A) (1997).
 Ariz. Rev. Stat. § 47-9315, provides in part that a security interest attaches to any identifiable proceeds of collateral, and the interest is a perfected security interest if the security interest in the original collateral was perfected but becomes unperfected on the twenty-first day after the security interest attaches to the proceeds unless a filed financing statement covers the original collateral, the proceeds are collateral in which a security interest may be perfected by filing in office in which financing statement has been filed; and the proceeds are not acquired with cash proceeds.
 Ariz. Rev. Stat. § 47-9601, provides in part that after default, a secured party may foreclose, or otherwise enforce the security interest by any available judicial procedure, and that the rights under this subsection are cumulative and may be exercised simultaneously.
 Under the doctrine of merger, after judgment has been entered on a contract, no subsequent action can be based on the contract, which is said to be “merged” into the judgment; any later action must be based on the judgment itself rather than on the underlying contract. See Restatement (Second) of Judgments, § 18 and cmt. a & b. Comment (1982); C & J Travel, Inc. v. Shumway, 775 P.2d 1097, 1100-01 (Ariz. Ct. App. 1989).
 Ariz. Rev. Stat. § 47–9601C provides that rights of a secured creditor after default provided in the statute are cumulative and may be exercised simultaneously.
 The code does not define when a secured creditor’s security interest in proceeds of collateral attaches, but assuming it attached in this case, at the latest, on the date the amended judgment for Nessi on the Sudovest note was docketed, September 12, 2001, Watson’s security interest in the proceeds was unperfected at the time she intervened to assert her interest in the judgment.