It has never stopped working once it's booted up... That's what really bothers me about the senero of a loose power/ground/harddrive cable connection...

Keep in mind that the player needs its maximum amount of current at bootup time. It's spinning up both hard disks and warming up the display all at the same time.

This lends credence to the theory that perhaps the power supply wiring to the player is inadequate. Have you looked here?