I've noticed this really annoying problem on my Loewe Nemos 32. Regardless of what I'm using the TV for (PS2, Laserdisc, DVD etc) I can see a verticle ripple effect scroll/pulse up/down the screen.
Sometimes it's very obvious, and sometimes it's almost impossible to detect. It's easier when something like a door frame or something long and straight apears on screen, especially if it is at the edge of the screen. It also affect the TVs OSD menus.
The ripple is noticeably bigger and slower when viewing PAL/50Hz material.

I'm guessing it is something to do with the power supply, but any info/ideas on how to clear this problem would be greatly appreciated.

[JayCee]

If you disconnect all external devices and the ripple is evident on the sets internal tuner it's more than likely a fault in the sets power supply.
It's not really a d-i-y repair unless you're experienced in handling electronic components and soldering.