Yes. I didn't realize you were using express checkout only. In that case, you would have to move the store cart summary and store cart details server behaviors to the confirm.php page as well, and you would have to update the bindings to use the persistent form bindings from the checkout page.
In this case, you might want to use a premier support ticket to get everything done efficiently. It is a bit more tricky to skip over since you were using express checkout.