Importing MXF - No sound in Comp

[insidedesign]

Alright, so I have several MXF files that are within my project file area. When I select them, I can clearly see that AE sees the audio - as indicated by the green wave graphics under the snapshot photo.

However, after I drag it down into my comp timeline and expand the waveform - the waveform is flatline. I do a ram preview with sound on, but there is no sound - the video plays silently.

Using the P2 Viewer, I test that in fact there is sound playing through my headphones when viewing it via the P2 viewer.

What am I doing wrong?

[insidedesign]

Our camera, the AG-HVX200, records with 4 channel audio. I noticed that our footage has no audio on channel 1, but audio on the other 3. Would this have anything to do with it?

[insidedesign]

I've been doing some playing around, and it looks as though Premier Pro supports my need of controlling different audio tracks/channels. Is it not possible to do this from within AE?