Yes, NvClock seemed to setup the regs correctly.... or so I think. I have a evga 5200 board.
NvClock starts with the correct values for the core and mem speeds. Tests indicate that NvClock changes the core and mem. But if I run a intense 3D game and a high core clock of 300 (based on NvClocks settings) after running the game the clock seems to reset to 250 Mhz. Might be the board thottling?
If need any testing I'm willing to help.