I never had good luck with QuickTime files. I tried using Dr. Divx to convert the Matrix Reloaded trailer into an avi, but it just freaks out and makes crap fly everywhere. I think Apple sells plug-ins for their player which can convert to/from mov files. (QuickTime Pro)
Uh, try using this. I haven't tried it, just google'd it.
Better yet, try After you get the mov to avi, use Dr. Divx or TMPGEnc to compress more.