CPU-z shows that turbo is enabled and is running stock clocks, given that it still shows a 20.5 multiplier.
I would try resetting the bios via "load optimized defaults" and reboot back into bios.
Now shutdown computer, clear CMOS when power is unplugged. Boot back into bios, hit "load optimized defaults". reboot.
Set your time and date inside bios.
Enable HPC mode (no real effect, just one of those things to turn on)
enable core control, and leave all 6 (may show as 3 pairs) cores enabled. This simply removes the "auto" setting.
Increase cpu-northbridge voltage (NB core) to around 1.3 volts. This is perfectly safe and wont hurt temps hardly. Now turn your northbridge speed to 2400mhz or 2600mhz. Great little boost in performance. May need NB core up to 1.325 if the cpu has a sourpuss of a memory controller.
Increase the base clock form 200mhz default to 201mhz. This may trigger the motherboard to actually pay attention to overclocks, and 1mhz wont upset the ram or anything to any degree.
ENABLE cpu unlock. I initially thought this was "core unlock" as there was a 4 core Phenom chip that could be opened up to 6 cores. THIS might be the setting you need to touch!!
Post back with updates
Be sure to pay attention to VRM temps if you can seee them via HWinfo64 (free software). If these temps go too high (over 80*C or so) the motherboard may decide to throttle the cpu down in frequency. Some motherboards dont like over 75*C, some motherboards dont care as long as its not on fire lol