Using an ASUS 636 for cycling I had repeatedly problems with sudden blackouts- hardresets during navigating.
As I am fixing the PDA in the original car cradle with a Richter bracket on my bar, I originally thought the sockt/plug combination would be the reason.
It is NOT. The hard reset is triggered by a regular micro switch for these very purpose located in the PDA, under the left little hook of battery compartment lid. Its job is to reset the PDA automatically when the lid is taken off. As the lid itself is not perfectly fiting it moves around and from time to time caused by vibrations triggers the microswitch...