Synchronize is Greyed out in Premiere CC, why?

[Rex Lint]

The Goal:  To sync an interview that involved 2 Nikon DLSrs, with external audio from a sound guy.  There are about 8 clips from each camera, and 8 audio files.

I tried to drop them all in a timeline and just select all and sync.  Sync was greyed out.  I then tired just 1 set of cam a cam b and audio file, sync was greyed out.

I then tried just selecting the audio waveforms form independently of the video clips, without the external audio...greyed out.

Not sure what I need to do.  Meanwhile I am in manual sync mode.  Good thing the team that shot this stuff is on it with slate and keeping the clips tight.

Any help would be awesome.

Thanks

Rex

[thepixelsmith]

You can't use synchronize when you have multiple clips on the same track.