SQL Error with user accounts
 

My forums has just started giving me error messages when anything user-account related is done ie. checking profiles, registration, etc.

Warning: mysql_query() [function.mysql-query]: Unable to save result set in /includes/class_core.php on line 395




Database error in vBulletin 3.5.2:
Invalid SQL:
SELECT COUNT(*) AS count FROM user WHERE referrerid = 1;
MySQL Error : Got error 127 from storage engine
Error Number : 1030
Date : Thursday, June 25th 2009 @ 03:00:04 AM
Script : http://www.*****.com/member.php?action=getinfo&u=1
Referrer : http://www.*****/usercp.php
IP Address :
Username : N8
Classname : vb_database



Any idea what might be causing this error?