In In re Marriage of Klebs, 196 Ill. App. 3d 472, 554 N.E.2d 298, 143 Ill. Dec. 363 (Ill. Ct. App. 1990), wife filed for divorce and a contest for custody of her daughter born during the marriage ensued. Some two years later, a judgment for dissolution of marriage was issued incorporating an agreed order granting the parties joint custody of the daughter while maintaining her physical residence with the husband. The judgment stated that the daughter had been born to the marriage. Soon after, the wife remarried. 554 N.E.2d at 301. About six months after the divorce, the wife filed a petition for determination of the paternity of her daughter. The wife also sought to vacate the portions of the divorce judgment establishing her former husband's paternity and granting him joint legal and full physical custody. The wife's petition revealed that blood tests taken about a month before the filing of her petition rather conclusively established that her current husband, and not her former husband, was the natural father of her daughter. Id. The trial court ordered the former husband to undergo similar blood tests, which yielded much the same result. At an evidentiary hearing, the wife admitted that at the time she filed the divorce petition, she had already begun to suspect that her daughter was not the issue of her former husband because she bore a physical resemblance to her current husband instead. Id. at 302. The trial court vacated the divorce judgment insofar as it found paternity in the former husband. The trial court held that "it was in the daughter's best interest to recognize that she had two fathers." The trial court further held that the current husband was "the biological father" but that the former husband was "the 'equitable' or 'psychological' father." The trial court did not, however, disturb the custody arrangements established in the divorce judgment. Id. On appeal, the Appellate Court of Illinois held that the trial court erred in ordering the former husband to submit to blood tests and in not dismissing the wife's petition. As to the latter error, the appellate court stated, inter alia, that: Certainly, the petitioner in this case was a party to the dissolution proceedings. Therefore, she may be estopped from raising the issue of her daughter's parentage and the finding of paternity, as set forth in the dissolution decree, may be heldres judicata for the purposes of her post-decree petition. Id. at 303.