Just to clarify things, you now have three modules of Corsair Dominator 1600Mhz RAM in the white slots. What model number?
What BIOS are you using now?
Have you got the power leads all connected to the motherboard, the 24 pin, and the 8 pin near the CPU ?
Have you got the power connectors attached to the garphics card?
What cooler are you using on the CPU?