I finally found time to test phpbbmotion with PHPmotion V3.5 and as I thought it works perfectly.

I’ve added a new feature to the addon, the bridge will now transfer any existing private messages from PHPmotion to phpBB on installation (as once the bridge is installed it uses phpBB messaging). If you’ve already installed the bridge and would like to transfer any old messages you can still do so easily, check out the changelog for instructions. I’ve also made a few changes to improve the session handling once a user logs out.

Upgrading is very straightforward simply download the new version from your client area and follow the instructions in the changelog, only two files need uploading.

For more information on  the add-on check it out here: phpbbmotion – phpBB3 and PHPmotion user integration