I’ve had my 770 three months. Last week, about 60% of the touchscreen stopped working. Mostly the area from the upper left hand corner to the middle of the screen. If I use my fingers and press hard it will sometimes respond but will not work at all with the stylus. I did feel over the past month or so that the screen was not responding as fast or as accurately as it should. In fact, from day one it seemed a bit sluggish (not the software the screen response and sensitivity) but now , it has almost stopped responding completely in a large area of the screen – unless as I say I use my finger and press very hard. Is this what I fear it is? A bad touch screen that can only be fixed by sending the unit away? Hate to do this as I’ve become very dependent on it!