S-Video out with radeon with 'Flyback Lines' showing on the TV

[uebershark at googlemail.com]

Hi!

I'm experiencing a weird issue using TV-out (S-video) with the
xf86-video-ati driver.

TV-out works, but I get weird 'flyback lines' on my TV screen.
Same setup running WindowsXP does not have these showing, so I can
rule out a connection problem.

The TV is rather old, connected via S-Video cable+SCART adapter.
I've posted about this here:
http://www.linuxquestions.org/questions/showthread.php?p=3963780#post3963780

The second posting has a photo-attached, which shows what I mean.
There's also xrandr output there.

So far, I've tried to adjust the output via Modelines, I got the ones
WindowsXP uses via PowerStrip as mentioned somewhere in the
freedesktop wiki, but that didn't help.

Any ideas what I could try?

Tom