I don't know if this is normal for a Wii or if mine has a problem .
Running through composite or component and tested on two different TV's I still have this issue .
When I play Virtual Console , NES or Sega Master System the picture is perfect . When I play anything else , SNES , TG16 , N64 or New Wii games , even the Wii Menu , I can see the scan lines or black dots , scrolling up , which makes a wavy picture . It looks like when you see heat rise from the concrete in the summer . Its kinda subtle , like you can still play the game but once you notice it , its really annoying . You can see the screen , scan lines , moving upward which cause the picture to look shaky .
Now I thought it was the TV or Power supply , ground problem , but when you play Virtual Console , NES or Sega Master system games it stops doing it and the picture is rock solid , perfect , scan lines don't move , and I didn't change a thing , no cable swap , nothing .
All the TV's I've played this Wii on do the same thing .