After updating Firefox, the browser is for some odd reason no longer loading stylesheets properly. I am a web developer and have been using Firefox as my main development browser for the past 4 months or so (used to use Chrome). As of the update, none of my pages are working properly anymore, INCLUDING a site that has been online and unchanged since before the update. I thought the issue was with my own code until I found that the online (unchanged) version was also experiencing the same issues. In looking at FireBug (in the Net panel), I found that ALL requests for CSS files result in a status of "Aborted". This includes a stylesheet loading from my own server, as well as stylesheets loading from LeafletJS and YouTube CDNs. I highly doubt all of these servers would all of a sudden become problematic, and as such I'm more or less 100% sure that the Firefox 18.0.2 update introduced a major bug that breaks websites. I have a screenshot of my FireBug net panel, and will try to add it to this post after I post it.