rip out that PSU before it blows up. You go and spend money on a nice GPU and you forgot the most important thing is a quality power supply. What you heve there is the cheapest of the cheap. Please replace it with an antec, corsair, seasonic or xfx psu. Theres still a chance that its not the cause of your problems, but its highly likely. Especially since its a known crap brand that absolutely will not produce its labelled wattage. Never ever, ever, ever, ever buy a cheap psu or you will regret it.