[Chuck Bengele]

I may have found the issue and a better fix. It appears to me that Premiere CS6 is losing the Audio Channel Mapping. Here is what I have found works:
1) Right Mouse Click on your clip in the Timeline.
2) In the drop Menu select “Audio Channels”.

* I found that the audio portions of my video clips had lost their “Left” and “Right” channel designations and reported as “None” under the “Source Channel” listing.

3) By correcting/adding “Left” and “Right” to the Source Channel setting, my audio was now once again happy and useable.

So far, so good and I get to use my original source material once again.

Seems like there should be a way to tell Premiere to “refresh” this data in the Project or Timeline.

Love to know if this helps.

Regards,
Chuck