Soodle,
there is no way you can do it wrong, by using the XBEMIDP patcher.
You must have either the ISO or the XBE/XBE's that you want to patch. Fire up XBEMIDP, click the '...' button, choose XBE and patch it.
If you want to patch the ISO, just click next at the first screen (XBE patching), click the '...' button, choose the ISO to patch and go. You might want to uncheck the 'create backup file' when patching an ISO.
This will patch *all* occurences of the media ID check, if it still won't work for you, you might have another problem.
Regards,
L!M!T