Database Error :- Help Please !!!!

[Ab.Nath]

Hi guys

I am getting this error meaning once or 2 times/day
i am not getting what it is causing can u please Tell me

What it is causing , it is there for many times and it happens suddently
my forum is quite big with many members
what can i do to eradicate this problem

help please

The message that it is seen is this : -

Database error in vBulletin 3.8.1:

Invalid SQL:

			SELECT post.pagetext, thread.threadid, thread.title
			FROM post AS post
			LEFT JOIN thread AS thread ON (post.threadid = thread.threadid)
			WHERE post.pagetext LIKE '%[img]%[/img]%' 
			ORDER BY rand()
			LIMIT 0,10;

MySQL Error   : Got error 28 from storage engine
Error Number  : 1030
Request Date  : Friday, March 6th 2009 @ 05:28:32 AM
Error Date    : Friday, March 6th 2009 @ 05:28:32 AM
Script        : http://www.~hidden ~.com/
Referrer      : http://www.~hidden ~.com/
IP Address    : ~hidden ~
Username      : ~hidden ~
Classname     : vB_Database
MySQL Version : 5.0.67-community

How can i remove this problem ???
please help anyone , please pleas