On my site I only ever have two banners on any page, either one at the top and one at the bottom of the page, or one at the top and one smaller banner on the side of the page. I'm not a big fan of banners but sites do need them to pay the server costs etc. I think 3 banners on a page is fine, the problem with the GP32X main page is that all three are bright yellow and animated which catches the eye 3 times
Maybe some other banners or non-animated ones will work better.