I also have this problem. I have a release day PAL Wii, a Samsung HD 50" Plasma and it's hooked up using OFFICIAL component cables. I get this static on the home screen and during play of any Wii game, WiiWare game and Wii Channel. Also, any PAL VC releases from SNES backwords also refuse to display. All NTSC/60hz games play no problem and Gamecube games look fantastic so I'm at a loss. I've tried ALL the settings, and also got the same problems on my Samsung 22" HD LCD TV that's in my bedroom. It's fine if I use the original scart but obviously the quality of picture is crap.
Any ideas? I tried contacting Nintendo UK but they were no help, asking me to update my TV's firmware but that hasn't helped :\