CPU-Z is reading my voltage as 1.456 when i have it set to 1.47 in my BiOS , this called Vdrop , and vdrop depend on motherboard. generally 1.425 - 1.45 get 4ghz for 965 BE .
It COULD be vdroop, but it could also be an incorrect reading. you will also notive the voltage will go up and down a bit depending on load and temperature. Dont worry about it. Just dont go crazy on the voltage or you will kill your chip eventually. If you can get it to 3.80-3.9 ghz with 1.5v then your pretty safe, from what ive heard, but every chip is different.