phpbb2 and site authentication systems integration

I took over on this big fansite that also has a forum (phpbb2) Fans can register and log in. When they register, we have to create a forum user account. When they log in, we have to also log them into the forum.

When they log out in the site or the forum, then they have to log out of both, etc. In other words: It should be as if the site and the forum is one thing. (even though they have separate user tables and stuff)

If I was on the project from the start, then I would have just used phpbb2's user table as the primary place to store users and then maybe add the fan info to that table or to some table that links to it, but it is too late now.

I'm sure I can figure out how to do this, but I simply don't have the time, so I was hoping someone else came across it and could point me in the right direction and maybe point out some pitfalls.

The only links I found that might be of value are:
http://www.phpbb.com/kb/article.php?article_id=143
http://forums.devarticles.com/showthread.php?t=5047

and I also posted here:
http://www.studiowhiz.com/forums/index. ... topic=6512