[EvilLS1]

Moonclamp,
I can give you a quick fix which will make it so that hidden users are never shown in chat (even to those who have permission to see invisible users).

In chat.php find:

 $somestuff = $DB_site->query("SELECT * FROM " . TABLE_PREFIX . "chatters WHERE userid=$userid");

	if ($DB_site->num_rows($somestuff)!=0) 
{
	$DB_site->query("UPDATE " . TABLE_PREFIX . "chatters SET chattime = $time WHERE userid = $userid");
} else {
  $DB_site->query("INSERT INTO " . TABLE_PREFIX . "chatters (username,chattime,userid) VALUES ('".addslashes($chatuser)."','$time','".intval($userid)."')");
}

Replace it with:

if ($bbuserinfo[invisible]!=1) {
 $somestuff = $DB_site->query("SELECT * FROM " . TABLE_PREFIX . "chatters WHERE userid=$userid");

	if ($DB_site->num_rows($somestuff)!=0) 
{
	$DB_site->query("UPDATE " . TABLE_PREFIX . "chatters SET chattime = $time WHERE userid = $userid");
} else {
  $DB_site->query("INSERT INTO " . TABLE_PREFIX . "chatters (username,chattime,userid) VALUES ('".addslashes($chatuser)."','$time','".intval($userid)."')");
}
}

I didn't test it but it should work.