Can you post (or Private Message) me the following:
* The login page you're starting from
* The URL of the 'login' article you're redirecting to
That will help us investigate what's happening on your site.
As for a temporary fix, the redirect to the custom registration page is performed at line 124 in the /components/com_jfbconnect/controllers/login.php file:
if ($redirect)
$app->redirect(JRoute::_($redirect, false));
I hope that helps,
Alex