Will lowering the default voltage hurt my system?

I recently built a system using the athlon xp palamino 1700. I downloaded the wrong spec sheet for it off amd.com and gotten the specs for the thoroughbred 1700. Anyway, stupidly I set the voltage to the default voltage of a thoroughbred 1700(1.5V). I ran it for a couple hours like that and it seemed fine. Then I realized that I dled the wrong spec sheet and quickly went to set the voltage at 1.75. I know that setting the voltage higher can hurt the cpu, but does lowering it hurt it too? It seemed to run stablely at 1.5 and I would like to set it back down there(its cooler).

Also I have a soltek sl-75drv5. The anti-burn shield is always higher than the temperature on my hardware monitor(usually about a 7 degrees C diff). Is that supposed to happen? If so which temperature reflects the temperature of my cpu?