Help optimizing this Query please

Hello:
i have this Query which is identified as a slow query.
i don't have any more tricks to optimize it:

("SELECT usergroupid,avatarrevision,reputation,user.posts,user.usertitle,user.username,user.userid,COUNT(*) AS total FROM " . TABLE_PREFIX . "user AS user," . TABLE_PREFIX . "thread AS thread WHERE postuserid NOT IN ($notop) AND postuserid=thread.postuserid AND thread.dateline BETWEEN $sttopthpo AND $endtopthpo GROUP BY thread.postuserid ORDER BY total DESC LIMIT 1");


here is it in the slow query log:
# Query_time: 11 Lock_time: 0 Rows_sent: 1 Rows_examined: 64
SELECT usergroupid,avatarrevision,reputation,user.posts,user.usertitle,user.username,user.userid,COUNT(*) AS total FROM user AS user,thread AS thread WHERE postuserid NOT IN (0) AND postuserid=thread.postuserid AND thread.dateline BETWEEN 1294444800 AND 1294531200 GROUP BY thread.postuserid ORDER BY total DESC LIMIT 1;



i have indexed:
user.userid
thread.postuserid
thread.dateline

but still it is slow.

any more thoughts?

 

Did you try indexing user.postuserid?

 

i indexed that, but i came up with another solution that i am working on now,
i will add another table and store the info in it once daily and make the script to simply read from that table instead of running this query every time a visitor comes to the site.