Mine was the GA-MA790GT-UD3H and it unlocked the 4th core of my Phenom II X3 720 just fine. Just set the first Advanced BIOS settings to Hybrid (instead of Auto), save, restart.... Very, very easy. Its now listed as Phenom II X4 40.
After setting up ACC to auto, it shows CPU as PII X4 40 but windows doesnt load.
Actually to be able to start PC I had to add 150mV to CPU, but even than Windows wont load (it report some random files missing)
Doest it mean that my 720 fourth core is REALLY malfunctioned or I'm missing something ?