I figure some hard core video pros will recognize this. The s-video input on my Intensity Pro has noise. I don't believe it is the source because if I plug it into my TV capture card this noise isn't there. I have moved the card to different slots, short cables, long cables, with not change. If I unplug the chroma line, the signal looks clean.
These pictures won't show you the details, but you can see generally what I am talking about. The lines aren't in the same spot, they are jumping around, and sometimes it will be a little more intensely concentrated at one or two groups of horizontal lines.