When viewing any page via iPhone, if the Toys 'r' Us banner ad is at the top of the page, the entire viewable browser area zooms in. I cannot pinch or zoom out, either. The site is basically unusable unless I hit refresh. The issue is resolved as soon as a different ad loads. However this causes me to lose my place regarding unread posts.
The issue persists after clearing history & cookies, and logging back in. This is on iOS 6.1.3.