Have.
You.
Tried.
The.
Updated.
Driver?
I don't think you were clear enough, lol. In the end, it is up to the OP, which is why I rarely repeat my recommendations in forums.
In the end, the OP is probably going to RMA his card, as he has done many, many times before. Not that he needs to, just predicting that is what he will do.
I actually almost never minimize full screen games anymore. Many years ago, I was playing a Star Wars game pretty heavily, which was based on OpenGL. That game killed the brightness of the desktop until you actually exited the game, so I got into a habit of just exiting the game when I wanted to do something else.