QT Pro 7 problems with sound.....

[forthebrave]

ok... QT Pro 7 has been working fine for me, besides sometimes playing .avi's back a little choppy, but now I have experienced some bad luck. Certain .mov files that I play, now have no sound. Other .mov's play back fine, but certain one's have no sound at all and sometimes freezes up. I read in other forums about this problem, but the funny thing is that I have a Logitech USB Headset and when I plug it in I can hear the audio from the once muted .mov file through the headset. I check my System Preferences and set my output to Line Out to my JBL Speakers and once again I can't hear the audio ( I can hear everything else though.. iTunes, etc. ) whats going on??