Not enough power or bad graphics card?

I just built a new system and ran into a problem early on.

New Parts

Asus M4A77TD
Athlon II x3 440
Asus ATI 5770 Graphics Card
GSkill 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600

Older Parts

500W Antec Earthwatts Power supply two years old
Phillips DVD R

On the first run, everything came up fine and was loading Win 7 64 until it got to Expanding Windows files. The fans all started full blast and the system froze after a few minutes. I could not get it any visuals on subsequent restarts, not to bios, nothing.

I swapped out my old graphics card an Nvidia 8800 GTS 512 with the ATI and was able to boot up, install Windows, etc. System is up and running.

Now, I assume that I just have a dud of a new graphics card, but before I RMA it, I wanted to ask if folks think my power supply is sufficient to handle the system and the new card.

Am I having a power supply issue or a dud of a card? I am suspicious since the new build with the new card booted up with visuals one time.

Any advice would be greatly appreciated. Longtime lurker here and I finally registered  

Cheers!