Success!
If anyone else if having no success commect out the following lines in secpay.php
use the following process from this topic:
http://www.oscommerce.com/forums/index.php?showtopic=27010
CODE
// tep_redirect(tep_href_link(FILENAME_CHECKOUT_PAYMENT, tep_session_name() . '=' . $HTTP_POST_VARS[tep_session_name()] . '&payment_error=' . $this->code, 'SSL', false, false));
And..from
tep_draw_hidden_field('callback', tep_href_link(FILENAME_CHECKOUT_PROCESS, '', 'SSL', false) . ';' . tep_href_link(FILENAME_CHECKOUT_PAYMENT, 'payment_error=' . $this->code, 'SSL', false)) .
delete the second HIDDEN callback process CHECKOUT_PAYMENT.
to leave:
tep_draw_hidden_field('callback', tep_href_link(FILENAME_CHECKOUT_PROCESS, '', 'SSL', false)) .
It works! (I swear I heard the Hallelajah chorus)
Wohoooo!!