can i limit mysql processes per user?

i have one client who has a pretty busy phpBB forum.

Every once in a while, mysql just locks up and other sites running vBulletin lock up and display a mysql error.

I finally was able to look at the mysql processes when the server was locked up, and found that this one phpBB user has 60+ mysql processes that are in a 'sleep' status.

Is there anyway I can make it so this user doesn't impact other users?

I had the same question and went to do a search :

http://directadmin.com/forum/showthread.php?s=&threadid=8770&highlight=limit+connections

Although I am still having a problem login into admin panel (tried da_admin & root) but still does not work (using admin password).

Peace,