I already did post in here:

But there is still no solution to solve the static problem with 10.6.x

Maybe somebody here now it and can help.

I have 1920 x1200 HD resolution on Dell 2709w
Geforce 8800gt now with Grafik enabler in Chameleon.
Tried also via EFI GFX string.

This happens sometimes when I start MACOS for about 20 seconds than it disappears . Also when Computer wakes up (sleepeanabler). When I turn off and on the monitor it disappears immediately .
Sometimes Snow just shows up sporadic.