looks decent , just dint like those fonts on top horizontal menu, you can keep them same as the side menus to keep a proper balance, rest all looks fine.
Why dont you give a color to your main page.Over all, you have used a lot of black color to your main page.Your forum page has a blue color, which is impressive. I also liked the buttons that you used, although they are not in a color form. Over all a cool site.
Overall I like the design. The colors are a bit bland and they can be improved. Try and use Text based main navigation (at the top). Image based navigations take a lot of time to load and also are not SEO friendly. Also, fill up the blank space at the bottom of the left and right columns. There is a lot of valuable space which can be used for a better purpose, by highlighting popular products, adding Adsense Ads etc.