Purple dots on screen

Question

I've had my Wii for over a year and today I noticed some purple dots flashing at certain locations on the screen. They are there on the Wii menu and during gameplay.I know it's not my TV, because my GameCube still looks perfect. I tried switching to composite cables, but the dots are still there with component and composite. The TV I'm using is a Hitachi 57 inch CRT HDTV that goes up to 1080i..