the source of your problem. LCDs have something called latency which means that they may not respond well to rapid changes. This is particularly true of inexpensive ones.
I just purchased a pretty powerful HP Pavilion a830n (http://www.exactchoice.com/profile_3266.aspx). The picture quality is just fine when I'm looking at a basically static image, but when I'm watching videos with a lot of movement (for ex, a video of a horse running) the video is very jerky and slow to react to quick changes. Could this because of a cheap video card? I don't understand why this is happening because my old computer (a Compaq Presario from around 5 years ago that is a lot less powerful) plays videos fine. Thanks for your input.