since your temps are back down, try a higher voltage to get a higher OC, not everybody's chip is the same, I have my voltage in the bios set at 1.425v but because of vdroop the voltage is really only 1.376v in cpu-z, the reason mine is so high is because I have a B3 stepping Q6600, Ghost probably has a G0, revision B3 doesn't OC as well as the G0 therefore I need to give it more juice, there will also be differences in G0s as well, as a rule of thumb from what I've heard the newer G0s don't OC as well as the older G0s, the older G0s overclocked like a beast even with lower voltages...
mine is stable at 3.06ghz (340 FSB) at 1.425v in the bios but 1.376v after vdroop is factored in...