Check your sleep state in the BIOS and your Windows power management settings in the Control Panel.
And update the BIOS if the CPU is not properly recognized, as noted.
edit: I fergit.
On one of the sub-menus (on the far right tab IIRC) in AOD there is a checkbox to lock your OC. It would probably be the most simple to set the cpu multi in the BIOS to 17, 17.5 or 18 in the BIOS (with maybe a slight bump in cpu voltage).
A similar bump in voltage with an OC to the IMC/NB would also help your performance in addition to your cpu OC.
Always check your temps ...