I'v just read this topic. Would you say that importing the contents and users of a phpBB3 forum would be possible with NinjaBoard, given the details below? I don't mind if I need to do some work in PhpMyAdmin or other tools like this, as long as you can give me directions.
phpBB3 version 3.0.4
There are about 1,300 topics with 4,500 posts and 1,600 attachment files.
There are about 300 registered users which of course should integrate with Joomla user administration.
The Joomla site is Joomla 2.5.9. At present we use a jFusion brigde for integration of the users of phpBB3. Also, we use Community Builder (version 1.9) on this site. This combination of user integrations is causing some troubles from time to time, after which we need to run repair scripts from CB or jFusion.