Clip cropped in playback window but not in project window
I am trying to make a movie of a music gala at my church. The video looks fine in the Project window, but the heads are often cut off in the Playback window. Also, when I exported it to iDVD and made a copy, the heads are cut of there as well. I've tried different property settings to no avail. It was importing as a 4:3 aspect ratio. Please help!
MacBook Pro, Mac OS X (10.6.7)