Today, while shooting a rodeo, I had the camera "Lock Up". It was working fine and I took a shot. Went to take a peak at the shot because of having difficulty getting a decent exposure from shade and bright sunlight. Anyway, I didn't get a preview and I noticed the green light indicating the camera was still writing to the disk was on. I waited for it to go off thinking there was a buffering issue. It never went off. In desperation, I turned the camera off, but it did not go off. I turned it on and off and tried other buttons too. No change. Finally I just removed the battery. Waited a minute and put the battery back in and all seems to be working fine. I am baffled at what would have caused this behavior. Anyone else have this or have any ideas. SD card was freshly formatted in the camera. Over 200 shots had been recorded on it today before the problem. After removing battery and putting it back in, the pictures still were ok and it continued to record probably about 60 more shots.