Version PHP 5.3 has a number of functions that are depreciated and earlier versions of PHPeSeller, PHPSecureArea and PHPKeyCodes will display warning messages identifying those depreciated functions when installed on PHP 5.3. It will still work as the functions are still there although they will be removed in PHP 6
To overcome this for earlier versions of the applications, in the error.php file just use
error_reporting(E_ALL & ~E_NOTICE & ~E_DEPRECATED);
This will stop the depreciated warning messages being displayed.