Audio issue when importing movie to iMovie 10.0.05- audio track doubles, is out of sync & one is pitched down
So I'm importing a movie I made using Logic 10 X (which I had imported so I could tighten up the audio there). The raw movie file from Logic sounds and look fine, but when I import it into iMovie and drag into a project to edit, the movie looks fine, but the audio sounds all crazy- it doubles the audio track, and the two are out of sync, and one of them is pitched down an octave or so. I've highlighted the clip and investigated the editor and it doesn't offer any clues about what's wrong- nothing odd in the adjust area of audio, or the speed (turtle icon) areas either... Is it just glitching? Am I doing something wrong (although I did exactly the same thing as my last import and it worked fine those times)...?
MacBook Pro 13″, OS X 10.11