Scott indicates that the source problem is often so random that it can't be pinpointed to specific brands, but it might help folks here to offer what their setups were (video source and cables). Stanley cup had problems with a Playstation2 and Monster S-video. I have not had problems with a Panasonic S-VHS VCR or a Panasonic DVD-A310 using both Monster S-video cables and BetterCables S-video.

By the way, kudos to Scott and the crew -- sounds like somebody's been doing some serious digging into video signal switching recently.