http://forums.nintendo.com/nintendo/board/message?board.id=wii_tech&message.id=85784
http://youtube.com/watch?v=xdWnsw3Yckc (not mine, I have green artifacts)
As titled, so turn off your Wiiconnect24 before it's too late.
Why do I mention this? Because I too have noticed green artifcats after buying Resident Evil 4 Wii Edition, I am in the process of calling and gettinig it repaired, I'll update as repair progress.
I am a PC gamer, and also have a NDS now, but without access to a Nintendo Wii until End of 2007.
Currently playing: Super Smash Brothers Brawl(Wii), Mystery Dungeon: Shiren the Wanderer(DS), Dragon Quest Heroes: Rocket Slime (DS), WiiFit(Wii)
Games Recently Beaten: Final Fantasy Crystal Chronicles: My Life as a King (Normal; Very Hard after the next DLCs become available)
1 word: RTFA
