I think it has to do with the lack of Powermizer support in Vista, the constant 3d mode. It's a problem with the nVidia drivers I think.
As for SuperPi, no idea...I don't need to benchmark my CPU to the nearest calculation per...
I tried these but when playing Tiger Woods 08, the display is totally screwed up, there are millsions of colours all over the place and its just crazy.
Went back to the stck Dell drivers, TW 08 runs like a dream!