08-11-2007, 05:50 PM
I am experiencing the exact same problem and it is driving me crazy.
I first exported it at Full Quality, then exported it using the Expert Settings at a much lower resolution (suitable for YouTube).
The low-res MP4 version works fine, but the Full Quality version visually freezes about mid-way through - while the audio marches on. The freeze occurs on the first frame of one of the imported video clips. This occurs on my Intel MacBookPro running 10.4.10 (iMovieHD 6.0.3) and also when playing back on a separate Windows XP Pro PC.
I tried moving the clip and re-exporting, but it still freezes on the first frame of that clip (even though the clip occurs earlier). I tried re-importing that clip. I tried importing that clip into an empty project and exporting it at Full Quality by itself - which works fine, but then importing that new clip into my larger project still fails in the same way after exporting again. I tried clipping off 1 second of that clip, re-exporting it alone, then importing that adjusted clip into my larger project - and it still freezes on the first frame of that clip.
Finally, I tried re-exporting a higher-res MP4, but that also fails and freezes on the same frame! This is driving me crazy. I am hoping clem13 found a solution, or that someone else has an idea of something to try...