It runs very well. Example www.dragon-clan.de

You have to download the latest PP5.5

In the boards directory you see the threads7.php, upload all files.
You have to change your PP configurattion from threads to threads7 and set the propper table prefix for the threads7 database (by default change from _w3t to _uubt). dont forget to change the path to your board.
After this done go phpmyadmin and backup the pp database. Go to pp_usergroups, delete all groups with ID higher then 4 (guest). Sync usergroups inside the PP admin panel and review the settings, save it. Then get from PP importer support boards the userfix script and let it run. This is needet because all IDs of the user inside Threads7 are changed.

Done. Works for me.

my board: http://www.dragonclan-forum.de
my hobby: http://www.biker-reise.de
Ich kann bei Fragen zu UBBthreads in Deutsch weiterhelfen oder es zumindest versuchen