Funny Thrice, I have just had the saem problem. I get green artifacts all over the place. This began after instaling the heatsinks. The card ran fine for weeks on stock cooling, then fine for a few minutes with waterblock, then installed the ramsinks and the card started artifacting.

I am going to try the card with waterblcok only tomorrow and see if that helps. I think it may be shorting somewhere. We will see.