Make the forums public. Your site will never grow otherwise.
Remove clutter from CMS. Less is more:
- Extra login box.
- Quick moderation. I'm not a moderator.
- Birthdays. Nobody pays attention to these.
- Calendar. Nothing to see there.
The header image looks tacky. I see what you're trying to do and it's a good idea, but I don't think it achieves the desired effect.
Remove the breadcrumbs from CMS. Not needed.
Customize this message for unregistered users:
"If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below."
Fix your navbar, there are 2 colors in there that don't match. It looks like the second part of the navbar is only there for advanced search, consider moving that elsewhere completely.
Trim down your forums. It's a ghost town in there and empty forums just make things look worst. Expand your forum as your site grows.
"Mark forums read" item looks out of place. Consider removing it completely or fixing the color to blend in.
Remove unneeded information from "what's going on" box on forumhome (icon legend, users today, users registered today).
Forget the "agree to rules" addon. Nobody reads the rules and trolls will be trolls regardless of rules.
I'm obviously being hypercritical, the site is nice. The color scheme is great. How did you achieve those dropdown menus?