Quote Originally Posted by lat9 View Post
Frank, the checkout_process functionality is untouched by the One-Page Checkout's processing. There might be, however, some changes that your application introduced into the checkout_payment/confirmation processing that are not getting picked up.

Are there any observer-class (i.e. /includes/classes/observers) modules that "help" with the operation? Or any additional header_php_xxxx.php files present in the /includes/modules/pages/checkout_payment or /includes/modules/pages/checkout_confirmation folders?
There aren't any additional header.php files or observers that I am aware of or can find but the vendor application does modify the checkout payment, process, shipping and confirmation pages. That should explain why the vendor application works with standard checkout process and not the one page checkout. I will try to merge these changes with the one page checkout files. I will let you know I make out.

Frank

Thanks for jogging my memory