[woostar]

ahhhhhhhhh - I think I know why....

These lines:

foreach ($allowedurls as $allowedurl) {
$message = (preg_replace('/(\[url=?"?\]?)(https?\:\/\/)?(www\.)?' . $allowedurl . '\/?"?\]?(.*?)?\[\/url\]/i', '', $message));
}

should be:

foreach ($allowedurls as $allowedurl) {
$allowedurl = str_replace('/', '\/', $allowedurl);
$message = (preg_replace('/(\[url=?"?\]?)(https?\:\/\/)?(www\.)?' . $allowedurl . '\/?"?\]?(.*?)?\[\/url\]/i', '', $message));
}

Will have to have a proper look at the code.

Maybe h2ojunkie can confirm.