i installed wordpress on my server, then i had to move my db, so i changed prefix and renamed all tables too, and now my wordpress isn't working properly You do not have sufficient permissions to access this page.
This should provide you with everything you need. I utilized it to change database names without a hitch back in October.
have you changed prefix as well? or just db? because it seems to be very easy to change host/db but not prefix inside of db