getting this weird database error with the vbadvanced home page now...?

[TheCaver]

im getting this error all the time now when people try to access the vbadvanced portal home page. it worked fine for about a week and it started randomly doing this today. Any ideas?

Database error in vBulletin 3.0.1:

Invalid SQL: SELECT 
				IF(votenum >= 1, votenum, 0) AS votenum, IF(votenum >= 1 AND votenum != 0, votetotal / votenum, 0) AS voteavg,
				thread.threadid, thread.title, replycount, postusername, postuserid, thread.dateline AS postdateline, IF(views<=replycount, replycount+1, views) AS views, forumid, post.postid, pagetext, allowsmilie, showsignature
	  		,thread.iconid AS threadiconid 
				, attachment.filename, attachment.filesize, attachment.visible, attachmentid, counter, thumbnail, LENGTH(thumbnail) AS thumbnailsize
				, avatarpath, NOT ISNULL(avatardata) AS hascustom, customavatar.dateline AS avatardateline
				, NOT ISNULL(subscribethread.subscribethreadid) AS subscribed 
				FROM thread AS thread
				LEFT JOIN post AS post ON (post.postid = thread.firstpostid) 
				LEFT JOIN user AS user ON (user.userid = post.userid) 
				LEFT JOIN attachment AS attachment ON (post.postid = attachment.postid)
				LEFT JOIN avatar as avatar ON (avatar.avatarid = user.avatarid)
				LEFT JOIN customavatar as customavatar ON (customavatar.userid = user.userid) 
				 LEFT JOIN subscribethread AS subscribethread ON(subscribethread.threadid = thread.threadid AND subscribethread.userid = 1)
				WHERE forumid IN(16)
				GROUP BY post.postid
				ORDER BY postdateline DESC, attachmentid LIMIT 10
mysql error: Got error 28 from table handler

mysql error number: 1030