In my case the banner ad was the normal size, it was just by itself at the top of an otherwise completely blank page. The issue only ever occurred on the ET site. It happened frequently, but not every time, when clicking on a link to a forum, and as described above only the banner ad would be displayed. But the odd thing was, that by then clicking on the back button, the desired forum page would be displayed, not the previous page from where the link was first clicked. It was acting as if it were automatically jumping ahead to an additional page that showed only the banner ad.