It's called Cool 'n' Quiet, the AMD equivalent to Intel Speedstep.
It's BIOS controlled, and in my experience great if you want to decrease idle power draw, but a nightmare if you've got any software that is reliant on CPU clock to control its internal timing count - Unreal Tournament engine games spring to mind here; if you install them with the CPU 'idle' they'll run in fast-forward due to the CPU clocking up to full speed when the game actually runs.
Run linpack or something similar, and you'll see all cores at their rated 3200MHz.
It's interesting to see the evolution of power saving tech for CPUs - initially it was a bit of a sledgehammer solution (all cores clocked up or down) then it evolved to a load-based scenario (all cores have independent clock states depending on load) and the latest and greatest versions (semi-)intelligently work out how much a core can be overclocked based on load, TDP and temperature.
So, no, there's no fault there. It's doing what it's designed to. If you want it running full speed all the time, disable Cool 'n' Quiet in the BIOS.