I have a 720x480 Quicktime movie created from a screengrab of a slideshow I did. The resulting Quicktime is very high and looks good. In iDVD, I burn a playable DVD of this movie. When I play it on my tube TV, there's a bit of letterbox effect going on because of the aspect ratio (which is fine, I like it) with black appearing above and below the 720x480 movie. The one thing I notice though is that the horizontal edge of the image seem to pulse and shimmy slightly. Perhaps it's because it's a tube TV and a few years old. I don't notice this effect if playing the DVD on my Apple LCD. I don't have a nice LCD screen to play it on to test. See illustration: http://www.pixentral.com/show.php?picture=1pmoAZxFAdAWWGN1NbLvCaamWNn86 Anyone know what causes this?