Just wanted to share this in case it happens to anyone else, it could save someone a big headache down the road...

I recently bought a new Canon 5DMIII and installed the updated EOS plugin for FCP to go along with it. When I pulled up Log and Transfer, none of the footage would transcode. Drag it to the bin, the wheels start turning etc but no new files are created. I wound up transcoding the footage in Magic Bullet Grinder since I already had that app, and I didn't have much footage to deal with so it was no biggie. But I had to know why this was happening.

Long story short, it was because I had the time code feature set to "free run". When I went in and changed it back to "record run", those clips would transcode fine. Even recording additional clips on the same card with the clips that were recorded in free run mode, as long as the individual clip was recorded in rec run mode, it transcodes just fine.

Anyway, avoid free run TC on the 5DM3 if you plan to transcode in FCP.
I'm shooting a week-long project next week... sure am glad I found this out before I shot all that!!

I'll post a link to this in the 5D forum as well in case this can help any of those guys...