I've actually received email from some people who where having the same problem with their home theater systems. By looking at this web page, they figured out it was their S-Video cable causing it. I never though this page would actually be useful to anyone!
This is a 1/2 size version of the frame I captured. I've cropped off a
section and blown it up so the effects are easier to see. This scene has lots
of blues, which is where the effects seem to show up the most.
Unscaled lossless PNG file (392k)
This is a 2x blow up of a section of the captured image. This one was taken while using a 10 ft. S-Video cable I bought for $7.85. Check out the artifacts at the edge of the car and the diamond interference pattern. What causes this? If you know, tell me. If you only have an 8-bit display, you probably won't be able to see the interference.
This is the same section of the same frame, this time using a 6ft cable that came with my JVC Super-VHS VCR. The interference is gone, and the picture is much better.
Here's a comparison side by side of the two images. The only thing different
was the S-Video cable used.