Well, after trying to update the forum software and make a modification to the forums to block spam, the forums stopped working.
I had made a backup before I started the modifications, but unfortunately the backup was corrupted and didn't contain any of the user data or forum topic data. To top it off, phpbb seems to have made changes to the underlying database, so previous backups weren't working either.
About the only thing I was able to save were the avatars. All the uploaded avatars from the old forum are now in the avatar gallery for this forum.
Bottom line, the forums had to be completely removed and reinstalled.
I apologize for the inconvenience