Need help with opencart. orders are not processing correctly

when customer checks out and confirms an order (last screen) the order seems to not have happened. So he clicks again and again and creates duplicate transactions. Payment processing is fine, he gets a confirmation (eprocessing network)
when I go to back end, I cannot find the order.
order does get created because if i select a previous order that was processed normally and in the URL change it to the new order number it shows up, however it cannot be modified ("internal server error" message).
to replicate is easy, just try to process an order.
Need this fixed right away