Had a near-catastrophic failure on my ride in to work this morning. My Dahon's handlebar stem was, despite my having checked it the previous night, not properly secured. When trying to sprint from a stop at a traffic light, it gave way and I found myself flat on my back in front of a line of accelerating mopeds and motor scooters. I managed to duck out of the way in time, and there was no damage to the bike or to me -- but it certainly woke me up! Anyone else have something like this happen?