Just in case nobody else able to get this working - as said earlier make the changes noted in page 2. Then make the following additional change to the "Process_button" function:
Code:
////////////////////////////////////////////////////
// Functions to execute before finishing the form
// Examples: add extra hidden fields to the form
////////////////////////////////////////////////////
function process_button() {
// These are hidden fields on the checkout confirmation page
$process_button_string = zen_draw_hidden_field('cc_owner', $_POST['payflowpro_cc_owner']) .
zen_draw_hidden_field('cc_expires', $this->cc_expiry_month . substr($this->cc_expiry_year, -2)) .
zen_draw_hidden_field('cc_type', $this->cc_card_type) .
zen_draw_hidden_field('cc_number', $this->cc_card_number) .
/*Start Debit Card Addon*/
zen_draw_hidden_field('cc_issue', $_POST['payflowpro_cc_issue']) .
zen_draw_hidden_field('cc_starts', $_POST['payflowpro_cc_starts_month'] . substr($_POST['payflowpro_cc_starts_year'], -2)) .
/*End Debit Card Addon*/
zen_draw_hidden_field('cc_cvv', $_POST['payflowpro_cc_csc']);
$process_button_string .= zen_draw_hidden_field(zen_session_name(), zen_session_id());
return $process_button_string;
}