Many of you probably already know this, but I will pass on the information for others like me who did not know.
I was taking pictures at an indoor track meet in a gym with horrible lighting. I took a picture of the runners right as the gun sounded to start the race. A guy came over to me and asked me not to use flash at the start because the flash affects the starting mechanism. I think he called it a gyro or something like that. Apparently the gyro relies on the flash from the starter's gun to start the timing system. My flash created some confusion. After that I waited until each race was well under way before taking pictures. In fact I turned my camera away from the start so that no one could accuse me of being the guy with the flash that screwed up the competition.

