If I am using anything higher than 1/2000 of a second the first frame I shoot is always under exposed by at least 2EV. All other pictures taken, as long as I don't turn off the camera, are fine. For example I set the camera to Manual, 1/4000, f1.4, ISO 1600, and turn off the camera or let it go to sleep. After turning on or waking up the camera I fire off four frames without changing any settings. The first one is always under exposed or completely black and the other 3 are fine. Can anybody else try this out?