Re: GeForce 420 Go on Kubuntu6.10:Desktop fixed on 800*600 rectangle area,not full screen
In your bug report I see:
(WW) NVIDIA(0): Unrecognized ModeValidation token "NoEdidDFPMaxSizeCheck";
(WW) NVIDIA(0): ignoring.
However, you didn't generate a verbose X log, per the instructions in the post I referenced earlier.