ever since she got it, whenever you try to watch Movies in fullscreen, after 2 or 3 minutes the screen turns black then it freezes... mouse pops up again briefly, but then turns black and screen wont respond at all (neither will mouse or keyboard)

Only way to get it right is to pull the power/manual reboot

Seems to happen a lot more when streaming video from the net in fullscreen...

Any ideas???

Have turned off screen savers and power saver mode etc and optimised it for watching video but it still happens constantly