When you're using iMovie to capture video from or export video to a FireWire video camera or DV device, avoid plugging or unplugging other FireWire devices (such as a drive, iPod, or iSight) into or from your computer.
Connecting or disconnecting devices during a capture or export could result in unexpected behavior, including:
- Corrupted video (including MPEG artifacts)
- Camera disconnection messages
- Dropped frames
If you need to connect (plug) or disconnect (unplug) a device, wait until the capture or export is complete.