In this module is an error.
After payment is done the module opens the wrong page and an order is not processed in the shop.
It opens checkout_succes.php and should open checkout_process.php.
Change in payment.php the next line

$strPostData .= "&merchant_redirect_url_ok=" . tep_href_link(FILENAME_CHECKOUT_SUCCESS, '', 'SSL');

into

$strPostData .= "&merchant_redirect_url_ok=" . tep_href_link(FILENAME_CHECKOUT_PROCESS, '', 'SSL');

That should fix it.

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