That sounds reasonable to me that it could be the drive cable. It is a very sparratic problem, I tried four or five times to get it to work while I was in the car, it kept on booting up no hard disk found, and then when I turned the car off all the way and restarted, it worked. And it worked the next 2 times I got in the car.
Could it be Kernel related in any way? The only reason I wonder is because of the lock-ups during synchronizing. That is when the problem started, and when the player seemed to be working fine, and I syncronized it again, the problem started all over again. I was thinking about reflashing the kernel and seeing if that helps.. what do you think?