The errors below most likely are caused by the PHP5.3, you might get something like below if you upgrade to PHP5.3

• Deprecated: Function session_unregister() is deprecated in /modules/Users/Authenticate.php on line 70
• Deprecated: Function session_unregister() is deprecated in /modules/Users/Authenticate.php on line 71
• Deprecated: Function session_unregister() is deprecated in /modules/Users/Authenticate.php on line 72

In order to fix it, you will need to replace lines 70,71,72 from:

• session_unregister(‘login_password’);
• session_unregister(‘login_error’);
• session_unregister(‘login_user_name’);

To:

• unset($_SESSION[‘login_password’]);
• unset($_SESSION[‘login_error’]);
• unset($_SESSION[‘login_user_name’]);