When i merge thread , i get Database error

[harpreetxi]

Database error in vBulletin 4.2.0:

Invalid SQL:
DELETE FROM activitystream
WHERE
typeid =
AND
contentid IN (SELECT postid FROM post WHERE threadid IN (339,251));

MySQL Error : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AND
contentid IN (SELECT postid FROM post WHERE threadid IN (339,251))' at line 4
Error Number : 1064
Request Date : Saturday, June 9th 2012 @ 10:15:04 AM
Error Date : Saturday, June 9th 2012 @ 10:15:05 AM
Script : http://forum.fckya.com/inlinemod.php...eadids=339,251
Referrer : http://forum.fckya.com/login.php?do=login
IP Address : 117.205.1.9
Username : H4ppy!
Classname : vB_Database
MySQL Version : 5.0.95



But if i refresh , or even go back its always done. how do i fix it ?