My 660 sometimes will not respond to the touch screen. It might work for months, then exhibits this issue. I just used it to save some locations for an upcoming trip and it worked fine. 10 minutes later it won't respond to the touch screen. I've done the routine of holding the power button down while pressing a finger in the bottom right corner. This brings up the screen calibration mode. In this mode, the screen seems to work, I can chase the little dot around for an eternity but it never exits this mode. Garmin support says to buy a new GPS, very helpful.... Anyone have any insight to what's going on?