What is your BIOS version? Have you checked to see if there is an update as I've seen threads where early BIOS can not take the quad without an update.
Your spec is very similar to mine apart from the mobo and mine works fine. Have you also changed your settings in BIOS for the load stepping and C1E as these are your energy saving settings in BIOS which will throttle back you quad to stock. Disable them if trying to OC above stock.