مشكله في قاعده البيانات Error Number : 145

Database error in vBulletin 3.8.2:

Invalid SQL:

SELECT COUNT(*) AS threads, SUM(IF(thread.lastpost > 1247667657 AND open <> 10, 1, 0)) AS newthread

FROM thread AS thread

WHERE forumid = 39
AND sticky = 0

AND visible IN (0,1,2);

MySQL Error : Table './anamoon_vb/thread' is marked as crashed and should be repaired
Error Number : 145
Request Date : Wednesday, July 15th 2009 @ 06:48:28 PM
Error Date : Wednesday, July 15th 2009 @ 06:48:28 PM
Script : http://www.ana-moon.com/vb/forumdisplay.php?f=39
Referrer : http://www.ana-moon.com/vb/index.php
IP Address : 188.161.155.25
Username : admin
Classname : vB_Database
MySQL Version : 5.0.81-community

ادحين افتح اي قسم بالمنتدى ويعطيني هاذا الايرور ..وش الحل ...؟