I've had problems with Firefox not responding and having to be closed via task manager for some time, some days happening several times, and some days not at all. I originally thought it was to do with Facebook, as I tend to have that open most of the time, but it seems to be happening with whatever I have open. Today it has got to the point where it is becoming unresponsive as soon as I open it. I've tried opening in safe mode, refreshing and have now downloaded the latest version. Don't know what's causing it, or what to try next. Help please!