I'm using the Log and Transfer tool in FCP 7 to import sxs footage from an external drive. All of the clips appear in the window, but about 20% of the clips after "transferring", a red exclamation point appears in a column that indicates "error: no data"

The file directories seem identical for the clips importing successfully and the clips that aren't. Does anyone know why this is happening or what I can do to solve the problem?

If that wasn't enough, some other clips, when imported to log and transfer, give a message in the preview window that says "this format not available for preview". All of the clips were copied off the cards in the same way, one folder per card. Looking in the directory for the "bad" clips, I don't see a single thing different or out of place.

It's causing me a lot of stress. The footage is very important. Any help would be greatly appreciated.