Audio not playing out of QT file (kinda) in QT 10.2

Question

So, I called up an old (and large!) HD file I had of a show I produced (ProRes 422, dual, stereo, etc.)
My default QuickTime Player (10.2) pops up... loads the file. I play it...  But NO audio plays! (Checked the internal volume, of course.)
Curious. I ingested it into FCPX. But... Sound (and picture) played FINE.
Curiouser... I loaded it into QT7, and the audio played fine THERE, too.
How can I get my audio to show up in QT10? (I'm including a screenshot of the inspector from QT10? There is show 48kHz discrete (stereo) channels.)

Answer 1

Mind giving me a step-by-step on how I actually execute this change in QT7Pro, and... how I "save" same QT file so it'll play as a QT10 file.
One work flow would be:
1) Open the file in the QT 7 Pro app.
2) Open the "Properties" window.
3) Select the audio track and open the "Audio Setting" tab in ther lower half of the "Properties" window.
4) Click the "Channel 1" ("Discrete-0") line in the "Channel/Assignment" window to open the "pop-up" and then select the "Left" channel assignment option.
5) Now do the same for "Channel 2" but select the "Right" channel assignment in the pop-up window option.
6) At this point, the "Channels" entry for the audio track in the top half of the "Poroperties" window should have changed from "2 Discrete Channels"
to read "Stereo (L R) as seen here:
7) Now you have two options for saving the file:
a) Select the "Save" File menu option to save the new channelization settings to the original file or
b) Select the "Save As..." File menu option to leave the original file unchanged and copy all of the data and changed channelization settings to a new filw with a different name. (Note: ProRes422 ref files may or may not play the video in QT X player so I recommend the "Standalone" option here.)
Basically, the first option is very fast but actually modifies the original file while the second option must rewrite all data to a new file which can take much more time.
Good luck...