Firefox keeps locking up, for want of a better description. It will minimize itself, and when I go to click on it, it will not open/maximimize or let me use it. It then also won't allow itself to be closed (by using the only option available, the x on the taskbar icon). I end up having to restart my computer to get it to go away and then work properly (for a little while) when I restart. Firefox used to be my favorite browser, but I'm getting really frustrated. It's updated and still won't work properly. Help. Please.