I need help to sort out this problem: I have a ready built website in test mode built with OsCommerce and with already installed WorldPay module. Callback works randomly. Meaning, sometimes it re-directs shoppers successfully to the correct [url removed, login to view] but other times it re-directs shoppers to the login page or the index page, which means that the orders are not reflected in the shop's admin. In these cases receive a confirmation from worldpay that test payment was successful, but since the order is not processed in admin I dont know the full details of the order.
I need to make sure that the whole process runs smoothly before going live. Christmas is almost here. I need to secure Christmas sales, so I need this to be solved as fast a possible.