Using the PayPal cart upload and IPN system works great, what I am wondering now is if there is a way for the customer to return to the payment screen with the correct items in the cart if they were to close the PayPal window or just want come back to pay at another time, rather than right after the transaction.
I can't imagine that the situation would come up often, but it would be nice to be able to provide the customer a link in their original order confirmation that they could click and be served the same payment screen as when they click checkout.
Hopefully that makes sense, and hopefully someone has figured this out before!!