I use Firefox for work. I generally have several tabs open, including Outlook, Yahoo mail and Facebook. It seems most of the problems come with Facebook. I constantly get the yellow bar across the top saying "A Web page is slowing down your browser." I have tried restarting in safe mode, disabling add-ons and so on. I don't know a lot of the nitty gritty of getting into fixing the slowness and crashes it also causes, so I'm asking for some clear help for a non-programmer.