1) Make sure your LDT Multiplier is set to 4 or 3
2) Check if your processor or motherboard will reach higher speeds by using the Ram divider. Remember to raise voltages. I would do 1.5 just to be safe.
3) If the processor and motherboard is capable of reaching higher speeds, then try raising the ram voltages. Also try loosening timings. If you do not want to loosen timings, use the ram divider.
4) If all of this does not work, I have no idea. Could either be that your motherboard can't handle ocs higher than 214, or that your processor is a dud.
6600GT PCI-E for sale/Trade. Check the FS/FT forums on tech-forums for details.