IE7 puts ad sites in the broswing history

[S.SubZero]

If I browse with IE7, and I hit pretty much any web site with banners or whatever ads, these ad sites get individually added to my browsing history. This means if I hit the 'back' button, instead of going to the page I was just on, it tries to load up another ad. I have a hosts file that sends a bunch of ad-centric domains to 127.0.0.1, which makes the ad not show up, but instead I have to hit the 'back' button multiple times to actually go back just one page. This is a problem with some pages that load several ads, and they ALL go to the history.

Is there any convenient way to make this *not* happen? Firefox does not do this at all, it's 100% reliable with knowing what the previous page actually was.