One other thing that has just dawned on me - the video capture I did is actually reversed. When you see the comb filter notches moving, they are moving in the opposite direction than what you might expect. I am very new at doing videos (using Windows Live Movie Maker and a web cam) and I'll have to see if somehow I clicked on something that made the web cam reverse image the video. If it's not easy to fix, I'm not fixing it!