I'm having the exact same problem with my JVC SVHS VCR - there is a vertical roll no matter what I am doing with it, and I have gone through cables and played with it as well - tried various inputs, etc. The OSD and the background screen are rolling together - perfectly synchronized. I whined about this in another post a couple of months ago, but don't recall getting any responses. The VCR works fine when I run it directly into the TV.

It makes no difference if I am playing a video or I am at the blue "no video" screen, it does the same thing.