it's all abotu testing
make sure everything u run regularly likes the new speed, then try a little more. And DEFINETLY dont exceed 41mhz.
I ran 805mhz for a month until i found Adobe Premiere 6 crashes, so i went back down to 784mhz and all is well
the difference was 38 vs 37mhz PCI. Who knows why? Overclocking aint an exact science