PP V5.62 & UBB.t 7.0.2
Settings are in PP's config-inc.php file. Specifically $database_bb should be the name of your UBB.t 7.x database, and $user_bb and $password_bb should be the UBB.t 7.x database user and password.
Under the PP Admin menu, Cookie Settings: make sure the path, prefix and domain match that of your UBB.t 7.x. Under PP Admin menu, Forum Settings: make sure the path to UBB.t 7.x is correct, make sure the Registration System is "threads7", the database prefix matches your UBB.t 7.x prefix (ubbt_ default), and that you select 'yes' to the last question.
PM me if you need more help. I've also got a successful random image custom side-bar running with UBB.t 7.x.
I also suggest adding links in both product navigation bars to make transition between the two seamless.