I'm not saying this to hate on you guys or anything, but whoever decided that this was the best way to front a forum for your site is – bluntly – wrong. It's pretty bad right now, and there are better options.
For example, use of a bridge – such as WP-United – could lead to integration of the WP User DB with a fully functioning forum software like PhPBB, vBulletin, SMF, etc meaning that you wouldn't have to have seperate logins for the two different sites and would have a proper, less troublesome solution for your forum package.
Hope I'm not stepping on toes here, but I thought I'd put it out there because right now, I don't think you're going to attract a large forum following with what you have here. If that's not your intention… fair enough. If it is, I really would urge you to reconsider the way you've gone about it.