Won't Start (sometimes)

Every once in a while, probably 2 or 3 times over the last 2 months, I turn the ignition key and the dash lights come on and then when I turn the key to start everything either flickers and clicks and the car starts, or everything goes out and the car doesn't start. When this happens nothing works, even the trunk release and door locks go out. What I have done to get it going is to unhook the battery for a few seconds and then everything seems to work fine. I never get any codes or know when it is going to happen. After the first time I reflashed my PCM with the tune that I have in there and it seemed to go OK for about 3 weeks then it happened twice in the last week. Anybody experience anything like this? I hate going to the dealership! I thought that maybe the car was not recognizing the key and disableing the car. but then I thought that it only disabled the starter. It's not a major issue at this point, just a nuisance (resetting the clock etc.) but maybe it is a precursor to something catastrophic.

Battery terminals are pretty darn clean. only 10,000 miles on this car. There is no corrosion or oxidation on the terminals and they are clamped down pretty tight. I am wondering now if maybe I have a bad battery cable or a bad chassis ground connection. As long as nobody thinks it's a computer issue I will spend more time trying to track it down.