Touch the northbridge. Is it really hot? Somehow I think that TMPIN1 might be your NB.
Look at my screenshot:
It SAYS CPUTIN on mine, but I can assure you that's the Northbridge. It was idling at 70c for a while until I decided to buy a replacement NB cooler. Now it's around 48c idle.
I think your TMPIN1 is the northbridge. Your Core temps are so low that they are not usable in any real way. They do not represent a real number so they must be discarded.
If you can feel the heatsink and it's not warm then your CPU is fine. Athlon II chips don't get hot, even if you push 1.6v through them. I know this from experience.
How is your case ventillation? I bet if you feel the NB heatsink it will be very very hot. I would recommend lowering the NB voltage to stock, and making sure you have good cooling (or stick a fan next to it and take a look at the temps)
Let me know what you find