PHP 5 OSCOMMERCE BUG

Hello! D:\xampplite\htdocs\linux\shop\admin\includes\classes\ipload.php on line 31 i did this:

instead of this:
________________________
// self destruct
$this = null;

return false;
}
}
}
________________________

biggrin.gif i did this:
________________________
// self destruct
unset($this);

return false;
}
}
}