Overclocked AMD 630 Question

[ManBP]

I am new to overclocking but have definetly done my research, and succesfully overclocked my 630 to 3.5ghz last night. Ran for several hours on Prime 95 and stayed stable. My question is i have an asus M4A78t-E Motherboard with a core unlocker feature and prior to overclocking i had all four cores going. Now there is only three running and i dont get the option to enable ACC when i boot up. Is there a way to unlock the fourth core while overclocked?

 

[henydiah]

in bios Advanced Tab / Advanced clock calibration