Here's another possible bug i found : i've been doing bracketing with ML, my main exposure was 30 seconds (it only happened with such a long exposure time, but i haven't test Bulb as main),
so 30 seconds for the correctly exposed one, 3 bracketings, iso off, so to have the over exposed one, ML turns to Bulb, but it stays on a black screen at the end.
Most of the time, i would simply turn the camera off and the canon firmware would say that one picture is still saving, then 2 seconds then sensor cleaning then off.
I put the camera on & the picture really is there and had finished a while ago, but it stayed on the black screen...