out of sync

Hello Everyone
I am having a problem with I- motion, when I bring in clips from F.C.P the audio is out of sync, I don't have a problem when bringing clips in from I-Movie . The problem started when I began the task of trying to work in green screen for the first time in F.C.P. I have F.C.P. 4.5 and motion 1.0.1. could anyone help me please? I also wonder if there is something I could do to stop the jerky movement of moving vehcals .
Thank you
Beatrice