I've had a stable 5DMkII with ML 2.3 on canon firmware 2.1.2 for over a year. Tonight I tried controlling the camera from EOS Utility for the first time since I installed ML. Now the camera is fried. It will turn on in auto mode, and take a still pic. I can access the Canon Menu, but not the ML menu only in auto mode. In manual mode, I can't do anything. Of course I have a shoot at 8am.