Audio Channel Configuration: unsupported clip

When looking at the Audio Inspector in FCPX, and making adjustments under Channel Configuration, some clips show Channel Configuration: Unsupported Clip. I cannot make any changes to the channel configuration. This seems to happen at random. When using part of a clip on the timeline, and using another part of the same clip on the same timeline, one clip may be unsupported, while the other one lets me use the Channel Configuration normally.

Has anyone else seen this bug? Has anyone discovered a solution?

Thanks,

Kurtis