[Xenon]

well what doy wou want to get exactly?

this part

FROM user,post,usergroup,thread
WHERE user.lastpost=post.dateline AND user.usergroupid=usergroup.usergroupid AND 

post.threadid=thread.threadid

is very suspicious and will take a long time, poor DB

if you tell exactly what ya want i can maybe optimize that code also

aslo as a tip for future:
lear to use significant variable names.
i don't know what $bob should mean, but $usersinthread would be clear.