Normally it spends the night in my multi-media dock but this morning it was just flat on my desk and completely unresponsive. Correction, I had a green notification light flashing.
Tried restarting it, no luck. I removed the battery then replaced it within second and it started up, with 100 percent charge. Whew!
I've had mine since day one and this was the first time I've had any real glitch.