Audition has stopped playing left channel audio--even for stereo files

Hi all,

I'm running into a very odd problem, and I don't know what to make of it. Any guidance would be appreciated. This morning, I opened up an audio project I'm working on in Audition, and realized the left channel wasn't working. I had just worked in this project on Friday with no problems, so I assumed my headphones had bitten the dust. But after playing other stereo audio on my computer in other programs without a problem, and experiencing the same issue in Audition with a different pair of headphones, I realized the issue seemed to be limited to Audition.

To be clear, the audio files are all in stereo, and the visuals within Audition show equal levels for the left and right channels, but the left just isn't coming through. I experimented by re-opening several of my completeted and archived Audition projects--none of them had the left channel, even though they'd been finalized previously without a problem. When I listen to the exported audio from those projects in other programs (VLC, for example), they sound fine; the left channel comes through loud and clear.

Could I have accidentally flipped on an option in Adobe Audition that would mute the left channel in all files for some reason? Google isn't helping me out.

Thank you!