Fix this code

Ok simple quick job.. i am trying to use my own custom phpbb login with the following code: define('IN_PHPBB', true); $phpbb_root_path = __DIR__ . "/community/"; $phpEx = substr(strrchr(__FILE__, '.'), 1); include($phpbb_root_path . 'common.' . $phpEx); $user->session_begin(); $user->setup(); $auth->login($Username, $Password, $remember, 1, 0); my login varable are set up like this $Username = $_POST["Username"]; $Password = $_POST["Password"]; It shows on the forum stats as the user being logged in however it still asks them to login? Whats wrong with my this? very small job just looking for a quick fix