Radio/Nav unit issue

Anyone run into this one?  Sometimes when I start the H3 up, the radio will come on to what I had been listening to when I shut it down and then it shuts itself off with a "thunk" over the speakers.  I can turn it back on and the same station comes up, but the clock is maybe 15 minutes fast and has to be reset.  I made an appointment for a couple of weeks from now and the service writer said he had never heard of that one before.  Then he calls me back about an hour later and said a woman just called him with the same problem.
 
Gonna have them do something about the left front "sag" problem when it goes in too.

Hmm.. I've had something like that before in our old Tahoe. When it was a year or so old, and still under warranty, we would often find the clock would be off by a little bit here and there. Everything else would seem normal upon start up. Ours turned out to be a defective battery. I guess it would sort of die, for brief moments (for lack of a better term) while sitting parked, and then cause the clock to be off. But it always started like nothing was wrong. Once the dealer put in a new battery, it never happened again.
 
That's about the closest experience I've had with anything like what you described. Granted, yours does sound different. Our radio never shut off.. in fact nothing out of the ordinary ever happened on start up, or while running.

I got it in to check at the dealer and of course, they could not find anything.  It has not done this for about 3 weeks.

Mine does the same thing.  I think it resets the clock back to 12:00.  It does the same "clunking" that you are talking about.  Not sure what it could be.  We have already replaced the battery cause of earlier issues, so I don't think it could be that.  Let me know what you find out if anything.