Just so you know the final CPU mhz speed is determined like this.
Muliplier * FSB = speed
so
5x * 100 = 500mhz
5x * 105 = 525mhz
6x * 100 = 600mhz
The bad thing about raising the FSB is that it raises the speed for other componants as well, and if any of them cant take it your OC will fail