Paypal Integration - Oscommerce

Currently we are using default Paypal Module on our Oscommerce website. When a customer makes the purchase using Paypal and decides not to return to our website we loose their cart info. We need someone to provide us possible fixes to this issue. We will like to keep our customers on our site at all time and still be able to use Paypal. Is that possible?? Anyway, need someone who has oscommerce/paypal integration experience.