Mysterious problem with phpbb2 integration

We’ve been creating a simple roster-page lookalike for an online community we frequent, but there have been some bogs along the way. We’ve the roster-part down pat but when we gave the files to the people administrating this online community they decided that it’d be a grand idea if the roster would integrate with their phpbb2 and pull appearance from the logged-in user’s phpbb2 template prefs. Back to the drawing board, then! We even installed phpbb2 on one of our sites here at Dreamhost, because we really don’t have much experience with this forum software.

Unfortunately we’ve hit a bit of a snag in integrating with phpbb2. We’ve followed the instructions in this article, which seem to work fine. If the user is logged in, we pull their style information from the database and everything works just spiffy. If the user isn’t logged in the roster-page defaults to the default phpbb2 template look.

Everything is working just fine on our server hosted here on Dreamhost. On the server of this online community, however, the roster has an un-wanted side-effect: if you go to the roster page, at all, it logs you out from phpbb2. This isn’t particularily nice, of course, so we’re trying to figure out what the problem is.

We haven’t been able to reproduce this problem ourselves, and don’t have access to the server of this community. We suspect register_globals being the culprit somehow, with phpbb2 logging users out as a security measure, but we can’t figure out why or how to correct it.

Would any of you experienced folks have ideas on how to go about rectifying this? At the moment we’re entertaining some really hackish thoughts like pulling the user_id directly from a cookie, and so forth…