Ok.
If, after proper installation these drivers, I go to Riva Tuner and OC @ 475/450, reboot, go to Riva Tuner again and it shows 350/400 on the sliders, then OC seems not to work, is that right? (startup setting is set to 475/450)
If so, how to make it work?

(previously I was using
169.04 and had no problems with it)