I am trying to get the payment gateway 'fast charge' to handle my Zencart payments. In order to do this, we modified the authorize.net payment module (authorizenet.php) and changed the payment URL from this:
this->form_action_url = 'https://secure.authorize.net/gateway/transact.dll'
to this:
this->form_action_url = 'https://trans.secure-fastcharge.com/cgi-bin/authorize.cgi'
Now when I try a test purchase, I get to the order confirmation screen, and when I hit the 'confirm the order' button it contacts the payment gateway and then gives me the 'Whoops! Your session has expired' screen. The payment does go through, but the customer isn't notified of this in any way. The order isn't completed on the zencart side. Fastcharge is saying that it should work but it is not, anyone got any ideas?



