//Sorry for English (I'm italian)//
I'm very happy to contribute to this sideware, with my 50D.
I installed ML yesterday and the first problem occurred is this: if "Shutter Button" is set to "Hold during REC (IS)", the pressing of "Set" button start take the video (red circle compare at top right), IS is running correctly, but the new pression of "Set", do not stop the movie taking.
In this situation if I full press the shutter button, the camera take a bunch of shot, but then every button do //nothing//.
I turn to OFF the power selector, but the screen say "//saving images, wait...//" So i open the battery cover.
If "Shutter Button" is set to "Leave unchanged" or to "Block during REC", all is working. (Set start and stop regulary the movie taking).