Is the voltage and speed stock? If it is you may want to make sure that your heatsink is seated properly, and making good contact, then make sure that you have a good thin film of conductive grease (preferably Arctic Silver 3 or Crematique)...not too much, not too little.
No it isn't stock, the voltage on my motherboard (GVAXP-U) only moves in % so I moved it up to 5% which is the smallest increment. The FSB is at 182, the multi is up from 12.5x stock to 13x the RAM is up +.1 volts. It's a 2800+ Barton (2.08 stock) running at 2275 with a good heatsink and fan. Water is my next upgrade because I want to go as high as I can! Damn OC is addictive.