I have one MP4 movie that plays just fine in QuickTime (I've run it from beginning to end without problem).
However, when I imported it into iTunes, it can load but cannot play. Clicking on the play/pause button does not work. Nevertheless, I can advance the progress bar to any point in the movie, but the screen just shows a still image of that point.
This is really strange since as far as I know, iTunes plays movies with QT.
So, what is the possible cause of this problem and how to fix it? Thanks in advance.
My environmental specs: OS X 10.8.4, iTunes 11.0.4 (4), QuickTime Player 10.2 (603.17).