Is this a fresh install or an upgrade? If you're installing fresh, ie - there's no data in the base you need to keep (posts, users, etc) then just hop into phpmyadmin and drop the whole database and start from scratch, see what that does... Sounds to me like the sql dump didn't include IF NOT EXIST commands...
that table, if i'm not mistaken, defines which userlevels can post, reply, create polls, etc.
ICQ me if you want some real-time help
213-164-680