When you play a file in like that in QT, you won't hear all the tracks. It will play like the first two, maybe. with a 5.1 discreet output like that, you might only hear the music tracks. If you want to hear it all, you need to go into QT Pro, SHOW MOVIE PROPERTIES, and click on the AUDIO TAB and make all the audio MONO or panned L & R. Quicktime can't play out discreet audio as far as I know. When I QC my exports, I have to go into those settings to set things to MONO so I can make sure it's all there.