After I updated to 31.1.1, when I go to some web pages the browser pretty much hangs, I can't scroll or navigate the page, and the firefox menus won't open (it is hung), but not SO hung that windows whites it out, just hung enough so that I can't do anything. There is no associated high cpu usage when this happens either. Every 20 seconds or so I am able to use it again but then it will freeze again. If I am on an unaffected web page, and don't have an affected one open in another tab either, nothing is wrong, everything works normally. For example, this page I'm on now where I am writing this question, is not freezing. But if I go to one of the suggested answer threads here, those pages do freeze. Also tigerdirect and futureshop websites freeze, but the weather network doesn't.