[Logician]

You first assign the variable value according to visited pages file name. See the lines around 580. Eg.

PHP Code:

 case 'memberlist.php':
    $userinfo[activity] = 'memberlist';
    break; 


Then in the section you mentioned, you check the variable value and display the who is online text like:

PHP Code:

    case 'memberlist':
      $userinfo[where] = "Viewing <a href='memberlist.php?s=$session[sessionhash]'>Memberlist</a>";
      break; 


This will work ok unless you have a file name clashing with a vbulletin file name. It is not very usual to have one except you are using "index.php" in your external directory. If this is the case rename it to "main.php" or something to avoid the clash.