For the first time, I am storing and editing video on an External HD in iMovie HD. In the past, I have always stored and edited the video directly from my main HD. In playing back the video in iMovie, I notice it is choppy and the picture locks up. I have not previously had this issue. Is this a concern when editing video from an External HD. I am using a Firewire connection. If this is a known issue are there any workarounds such as transferring the video file to the Main HD? If I burn the video to a DVD will I still have the same concern? Thanks for any assistance.