[kh99]

You might try experimenting with putting the sessionid on the urls (which is done automatically if a user has cookies disabled). There's a function $vbulletin->session->set_session_visibility($invisible) which is called in init.php to show or hide the sessionid depending on a few conditions.

I haven't tried this and I'm not sure why sessionids are normally hidden, except that it makes the urls more readable, so maybe there's an issue with doing this that I don't understand.