Plaintiff leased tanning equipment to debtors, and the lease was secured by both the equipment and debtors' home. Debtors filed a chapter 13 petition and submitted a plan providing that the equipment would be surrendered to plaintiff, and that any deficiency would become an unsecured claim, the amount of which would be determined at the confirmation hearing. Prior to confirmation, debtors returned the leased equipment to plaintiff. Plaintiff then filed a proof of claim for the full amount owed under the lease, inadvertently listing its claim as unsecured. No reduction for the value of the returned equipment was made. Debtors did not object to the proof of claim, and plaintiff did not attend the confirmation hearing. The order confirming the plan provided that surrender of the equipment fully satisfied plaintiff's claim. Plaintiff filed an action to set aside the confirmation order and to modify the plan to reflect it as a secured creditor. The bankruptcy court granted debtors' motion to dismiss, and plaintiff appealed. The district court affirmed on the ground that plaintiff's lien had been satisfied, but specifically rejected the bankruptcy court's position that an order of confirmation could avoid an otherwise valid lien by operation of law. The court considered the bankruptcy court's ruling to implicitly value the surrendered equipment as equal to the value of plaintiff's claim, and concluded that plaintiff, by its failures to object to the plan, appeal the order confirming the plan, or argue on appeal that the plan did not satisfy the requirements of 11 U.S.C. § 1325(a)(5), was estopped from asserting that surrender of the equipment did not fully satisfy its claim.