heng1028, one thing that is helping FSB stability, is better cooling of the northbridge. Slap a BlueOrb on it. It drops the temp, in most cases, about 9°C, thus increasing stability.
But in your case, I'm with compuwiz1. You can also try a better cooling solution for the CPU and increasing your vcore voltage. What's your vcore voltage at now? What heatsink/fan are you using? What's your CPU temp?