As of yesterday a few of the websites I use every day have started looking strange, but only in Firefox. It seems to be pages that use CSS and the problem seems to be that the styles aren't working, so everything looks wrong. One of them (and the link I have provided below) is my own website which now just looks like a stack of boxes and I know it's how it would look if the browser wasn't reading the stylesheet correctly. However it's also happening on Facebook and other sites too. It all looks fine in Explorer.