I think you need more power. Go all out with this one:
Antec TruePower 2.0 TP2-550 EPS12V ATX12V 550W Power Supply 115/230 V UL, TUV, CB, FCC CLASS B, CUL - Retail
http://www.newegg.com/Product/Product.asp?Item=N82E16817103932
That's my future power supply right there unless I can find a 600watt one. That one should be good for you.