Hey, im also having this problem with my wii =/
Green pixels would appear every now and then when i play zelda, usually appears during sunset, or near water.
I tested on 2 different TVs and the problem still occurs. When i switch to the composite cables, i still notice the green pixels. They dont stand out as much compared to the component cables since everything is so blurry in zelda.
I will try calling the technical support to see if the warranty can cover this issue.
Well guys I had a friend bring over his Wii to try out the cables and it is in fact, my Wii GPU that is malfunctioning Sad story, but at least I figured it out... His game looks crystal clear with the component cables, and unfortunately not with mine
I called Nintendo Tech and they said they'll replace the Wii for free, so it's cool.. It's just gonna take a while, so no Zelda for me for a while :\
If you guys are having the same problems, get a friend to hook up his Wii at your house, and see if it's that..