I just want to second the new PSU recommendation. One with active PFC (which yours doesn't have), greater than 80% efficiency rating, and enough amps. The quality brands usually recommended are: pc power and cooling, Seasonic, Corsair, and Antec. This is based on reviews like those found on johnnyguru.com.
Here's one to consider:http://www.newegg.com/Product/Product.aspx?Item=N82E16817139003