database error

[nikson]

i get error on my site when someone tries yo register
the error is here

 
<!--
Database error in vBulletin 4.0.5:
 
Invalid SQL:
DELETE FROM vbstopforumspam_remotecache WHERE date &lt; DATE_SUB(NOW(), INTERVAL 30 MINUTE);;
 
MySQL Error   : MySQL server has gone away
Error Number  : 2006
Request Date  : Thursday, August 12th 2010 @ 09:36:47 PM
Error Date    : Thursday, August 12th 2010 @ 09:37:20 PM
Script        : http://www.desijannat.net/forum/register.php?do=addmember
Referrer      : http://www.desijannat.net/forum/forum.php
IP Address    : 94.192.85.64
Username      : kaolksd
Classname     : vB_Database
MySQL Version : 
-->

plzz help thank you