I not sure if this bug is the result of one of my in-camera (canon menu) settings, but I don't think it is.
I have reset all my settings and tried various legacy 'clean installs' of ML to see when the problem 'began'. I tested these builds:
October 23rd Nov 14th Jan 16th Feb 12th
I found that with clean installs of the above, I could only review a .raw movie file that I had just recorded (using the same build version), using the Oct 23rd build!
I haven't found any mention of this problem anywhere else in the forum, or on the bug reports, and it seems really likely that someone else would've discovered it by now, but I guess it's possible that people aren't reviewing their footage much (or at all!) in camera.
Anyhow, as I said, the Oct 23rd build is the only one that works correctly. The other three more recent builds that I tested simply display a series of garbled letters, numbers and symbols across the top third of the screen, and certainly no moving images.
I would send a screenshot, but I can't figure out how to 'print screen' when the module seems basically crashed.
Any work on this would be massively appreciated, I'm having to shoot tomorrow with the Oct 23rd build, just to be able to give the promised "B&W, 10fps" review feature to the client.
Excellent work everyone involved, I really want to learn coding.