I *really* need help with getting this online users thing working..

I think the online vbulletin script works with cookies and with a timeout option. The onlinescript by Slip counts all userid's in "session". So the results are different.

Compare in index.php from vbulletin:

if ($displayloggedin) {
  $datecut=time()-$cookietimeout;

  //$loggedins=$DB_site->query_first("SELECT COUNT(*) AS sessions FROM session WHERE lastactivity>$datecut");
  //$totalonline=$loggedins['sessions'];
  $loggedins=$DB_site->query_first("SELECT COUNT(*) AS sessions FROM session WHERE userid=0 AND lastactivity>$datecut");
  $numberguest=$loggedins['sessions'];
  //$numberregistered=$totalonline-$numberguest;