On some sites, for some reason, many of the thumbnails do not show up for me. The problem is, these thumbnails are hte links that I need to click. For instance, gorillamask.net, only three or four thumbnails show up on the page of the 30 or 40 that should. And other sites like dailysixer.com, many of the thumbnails don't work. This seems to happen for firefox AND internet explorer, although firefox is my main browser. Why would this be happening?