When I import audio files into Logic 8 project, I get a "file empty" error.

Logic Pro 8

OSX 10.8.1

These files were originally m4a. I've tried converting to aiff in Compressor and Quicktime but nothing. I know they are there because I can listen to them in Preview and iTunes. Stumped.

Note: this is the first project on my new MBP and OSX10.8.1 (old one died) I wonder if that has something to do with it.