First of all congratulations ! Some feedback : on IE9 at the registration page the textboxes appear emtry (no username,password,confirm passwork text) , a visitor would probably hit the back button !
Thanks for pointing that out - my IE testing has been sporadic at best! I'll definitely take a look at that.
Also , as patio11 mentioned a better visual design would be helpful for your site. You may find great templates for a low price at http://themeforest.net/