Invalid SQL: SELECT smilieid, smilietext, smiliepath, smilie.title

[Mean]

Sometimes, when i attempt to open a page, or new thread, it gives that database error.
How to fix that problem ??

PHP Code:

Database error in vBulletin 3.6.8:

Invalid SQL:

                SELECT smilieid, smilietext, smiliepath, smilie.title,
                    imagecategory.title AS category
                FROM vb_smilie AS smilie
                LEFT JOIN vb_imagecategory AS imagecategory USING(imagecategoryid)
                ORDER BY imagecategory.displayorder, imagecategory.title, smilie.displayorder;

MySQL Error  : Got error 12 from table handler
Error Number : 1030
Date         : Thursday, October 4th 2007 @ 10:00:18 PM
Script       : http://www.forumistan.net/yeditepe-universiteliler-buraya-t6885.html?p=14234#post14234
Referrer     : http://www.forumistan.net
IP Address   : ***************
Username     : CΛSTΞX
Classname    : vb_database