[Kriek]

Alesis, you attempted the first method, please try these.
(Also consider trying without the forward slash)

Method no.2

PHP Code:

". iif(!$WOLguests, " AND session.userid = user.userid", "") ." 
AND session.location NOT REGEXP '/vbTT.php' ORDER BY user.username"); 


Method no.3

PHP Code:

". iif(!$WOLguests, " AND session.userid = user.userid", "") ." 
AND session.location NOT RLIKE '%/vbTT.php%' ORDER BY user.username"); 


Method no.4

PHP Code:

". iif(!$WOLguests, " AND session.userid = user.userid", "") ." 
AND session.location != '%/vbTT.php%' ORDER BY user.username");