My D800 locked up on me today. I managed to work my way down to the collapsed I5 bridge near where I live by telling them I was with the press. I was shooting away when everything stopped and the camera seemed locked. Screens worked, green light for the card was stuck on. Not a good time for this to happen. I was getting some good shots of the media circus surrounding the bridge failure. I powered the camera off which did nothing. Did a two button reset which didn't work. Finally shut the camera off and pulled the battery for about 30 seconds. This worked and everything started working again. Has this happened to anyone else? Should I be worried there is something wrong with my camera?