Dien & Gordon,
I agree with Michael & Sandi.
Multiple forums is just too distracting and confusing.
You could however try this: have sub-forums.
DigitalPoint has done this.
http://forums.digitalpoint.com/
You can see how some of the forum categories have sub-forums under it. (The first forum - "Google" has so many sub-forums under it.)
vBulletin allows that. Maybe this will help:
http://www.vbulletin.com/forum/showthread.php?t=158708