Although you refuse to say it, I think I know where the fault in your thinking is. Many people up the voltage to their CPU as they hit higher and higher frequencies. This can help stabilize a CPU if its right at the edge. This isn't the case of more frequency = more voltage, so less frequency = less voltage. I'm not 100% sure why upping the voltage helps stabilize a CPU, although I'm sure it has something to do with helping the transistors switch on and off fast enough at the increased clock speed. Remember that a transistor on the 65nm process can switch (at a lower voltage to) faster then a transistor on the 90nm process. If you want a 90nm transistor to switch as fast as a 65nm transistor, you'd probably have to give it more juice, though why that works I don't know.