I leave my computer on all the time because I have to for my work. When I leave Firefox running on my computer and I don't touch it for two days, the first thing it does the next time I touch it is go into "Not Responding" mode. This, to me, is the most frustrating thing about Firefox. If your program is smart enough to know that it is "not responding" then kill the thread that is not responding and report it to yourself so you can fix it so Firefox doesn't go into "not responding" ever again. Don't your programmers know what to do when a timeout occurs????? Then, after I kill the program (using Task Manager or whatever), I start it again. When I start it again, it "applies updates" so it runs "Firefox Update". And, of course, the same programmer wrote Firefox Update and it reports "Not Responding" when it begins the process of "Checking Compatibility of Add-ons". Guess what, if your program goes into "not responding" and goes completely to sleep when it is checking compatibility of add-ons, you should start without any add-ons. It really is not hard to be a better program. Don't be lazy. Get it fixed!