Slow Queries forumdisplay
 

Can someone help me optimize this query as it happens all the time. These queries appears at forum ID 96 I have there like 164,833 threads and 418,405 posts. And I can't figure out what is wrong.

HTML Code:
# User@Host: forums[forums] @ localhost []
# Query_time: 11 Lock_time: 0 Rows_sent: 100 Rows_examined: 116077
SELECT threadid , title, lastpost, replycount
FROM thread AS thread
WHERE forumid = 96
AND visible = 1
AND open 10

ORDER BY dateline ASC
LIMIT 5000,100;
# User@Host: forums[forums] @ localhost []
# Query_time: 11 Lock_time: 0 Rows_sent: 100 Rows_examined: 115777
SELECT threadid , title, lastpost, replycount
FROM thread AS thread
WHERE forumid = 96
AND visible = 1
AND open 10

ORDER BY dateline ASC
LIMIT 4700,100;
# Time: 060609 19:52:25
# User@Host: forums[forums] @ localhost []
# Query_time: 12 Lock_time: 0 Rows_sent: 100 Rows_examined: 116177
SELECT threadid , title, lastpost, replycount
FROM thread AS thread
WHERE forumid = 96
AND visible = 1
AND open 10

ORDER BY dateline ASC
LIMIT 5100,100;
# Time: 060609 19:52:26
# User@Host: forums[forums] @ localhost []
# Query_time: 13 Lock_time: 0 Rows_sent: 100 Rows_examined: 116377
SELECT threadid , title, lastpost, replycount
FROM thread AS thread
WHERE forumid = 96
AND visible = 1
AND open 10

ORDER BY dateline ASC
LIMIT 5300,100;