A movie freezes (audio still running)

    Jan 09 2013 | 7:17 am
    Hello, I am a beginner. I am playing mov file with 'jit.qt.movie', but it always freezes at the same point. The sound doesn't stop though. The scene is just after an speeding scene. I sped up the clip in Final Cut Pro X (not in Jitter), and exported the mov file.
    Many thanks,