Streaks shooting across screen

[Jon A.]

My 1973 Chromacolor and 1977 Trinitron show short, multi-colored streaks shooting across the screen when playing a DVD. They usually show up one at a time and cross higher and higher before starting again from the bottom. I thought it was an issue with the Zenith until I fed my Trinitron with the same setup. This does not happen with my 1987 Electrohome, so it must have something to do with the design of the older sets. What gives and is there anything I can do about it?