Any one got a Gigabyte HD 7970 OC--voltage control?

just got a new Gigabyte HD 7970 OC 1ghz edition

no matter what software i try with ie gigabyte oc guru 2 or msi afterburner or evga precision it wont let me increase voltage

voltage control is working as i can lower the voltage ok but it wont go over the default 1.170v

any one know if gigabyte have started blocking increasing voltage on this as the reviews i read before buying it showed

people increasing voltage and getting to 1200mhz-1300mhz

getting 1000mhz default and cant overclock past 1050mhz

though memory overclocked from 1375mhz to 1600mhz no problem--havent tried higher on the memory yet

but have tried both bios by moving the dual bios switch and nothing i have tried will allow voltage increase

this cards model number