This is what I get when I do Get Info on any mp4 file on my computer or hard drive
Am looking for something more in the way of a detailed report such as the following:
The above stats are for another MP4 file that is not QL compatible, does not open in QT X, opens and plays the audio in QT 7 with a "black" display, and plays normally in VLC:
QT X Player
Plays like this in QT 7
Plays like this in VLC
And plays like this in QT X after reconverting the file using HandBrake. And all of these images refer to just one possible issue—in this case the use of the High 4-2-2 Profile for an H.264 encode.
Have already indicated what you could try to do to fix the issue in terms of a "general" workaround. Did it work? If not, try posting a sample file that can be downloaded and examined by several different people who may approach the problem from different angles.