OK, so the updated power store files fixed the mail sending problem, but now the redirect to the success page is not working.
To trouble shoot the redirect issue, add the following code at line 1 of the confirm page:
<?php
error_reporting(E_ALL);
ini-set('display_errors','on');
?>[/php]
most likely, a php error is occurring that is preventing the redirect. this code will turn error reporting on, post back any errors you see so we can troubleshoot the issue.