I had this same problem when I installed my C3 stepped 955 BE CPU. My BIOS was underclocking it to a x4 multiplier.
This is most likely the same cause for you, check your BIOS as well as windows based programs like CPUID, AMD Overdrive etc etc.
See what your clock is, like I said mine was 800 MHz.
I was required to flash my BIOS then it worked fine.
First thing to do is check what your actual clock speed is, then flash the bios if its anything less than 3.2 GHz.