Screen going to black HD 6770

[AlteredTomorrow]

I'm having an issue with a new video card I purchased. I bought the ATI GFX Radeon HD 6770, and installed it with a 500W power supply (it recommends 450W minimum.) On certain games after a period of play (the period seems random) the screen will go black for a few seconds then return to the game. It doesn't happen with all my games, only two that I've noticed so far: The Witcher 2, and now Skyrim. For Skyrim it took a very long time before it happened but on the Witcher 2 it happened within a couple minutes of play.

This did not happen with my older card.

What is the cause of this and is there a solution?

 

[AlteredTomorrow]

Bump, does anyone know?

 

[dannyflorida]

Bump, does anyone know?

Same thing is happening to me. I look forward to someone responding.

 

[LightVice]

Same here.
Except SC2 for me.