I am getting this when trying to use who's online feature in VB 4.1.4

Code:
Database error in vBulletin 4.1.4:

Invalid SQL:

	SELECT IF(userid > 0, 1, 0) as isuser, COUNT(session.userid) as online_users
	, user.vbet_def_lang AS vbet_def_lang
	FROM session as session
	
	WHERE session.lastactivity > 1310867974
	
	
	
	GROUP BY isuser;

MySQL Error   : Unknown column 'user.vbet_def_lang' in 'field list'
Error Number  : 1054
Request Date  : Sunday, July 17th 2011 @ 08:29:34 AM
Error Date    : Sunday, July 17th 2011 @ 08:29:34 AM
Script        :*/online.php
Referrer      : */forum.php
IP Address    : 122.177.110.35
Username      : Avinash
Classname     : vB_Database
MySQL Version : 5.0.92-community
can anyone help?