Forum Moderators: rogerd
Also, I've found that people who use the boards and the main site tend to be different animals, although I'm not sure if you will get a lot of common users with different forums.
Based on my experience, I would suggest letting each forum have its own users database, unless you can do it without a hack (such as the Eve forums).
I think you could look at syncing them so they both contain the same data, like a multiple insert when they register to insert that data into all the dbs.
I think you will end up hacking a bunch of stuff trying to get multiple dbs to use a single table. You would then have to redo it every time you need to upgrade or patch as well