dvd - stinking retrace lines

[frenchy]

I have played my really old laserdisc player on my old tvs before and never had a problem, so tried my Sony dvd player with Revenge of the Sith on my ctc-10 tonight and get these stupid 'data' lines. (see pic) Tried other discs, same thing. They appear for 15 seconds, then fade away for 5 seconds, etc etc. They only appear if a disc is playing, not when the player is in screensaver mode. And when they are on screen they give me a nasty sound buzz too. The picture and sound are gorgeous if not for these damn lines. If I turn the contrast waaaay down they almost go away... but then so does the picture quality!
I'm running the dvd signals thru rca cables into a little ac/powered video-to-rf gizmo and a coax from that to the tv's antenna splitter.
Am I stuck with this? Would maybe a different player not do this, like maybe an older one that has a coax output on it? I know this happens on certain broadcast channels but thought it didn't happen with dvds. thanks!