I've detected a break in my timeline that I cannot get rid of. With a magnification to 1 frame I found a mysterious "razor-like" cut in the space between my video and audio timelines. When I try to razor cut around it the little booger moves. It has created a flicker that is not noticeable on a burned DVD, but it is visible on an exported tape. What is it? What causes it? And how can I get rid of it?