I purchased this graphics card for my Mac Pro from the Apple Store in Early Jully 2008 after my ATI card died. I have only had it a month and all of a sudden I am getting artifacts appear on the screen. They do not happen immediately but within about 20 minutes of the computer starting. I have done the following with no effect : 1. Removed the card and reseated it. 2. Reinstalled the 10.5.4 combo update. 3. Reset PRAM and power management 4. Installed Leopard on a different partition (same problems arise) I want to point out that the artifacts appear even when the card is underutilized (reading email, browsing the web). What is more worrying is that when the screen is black (watching a video or just using a black wallpaper) I get flashing lines across the screen. Take a look at the problems: Geforce 8800GT Problems I know that my monitors are ok because the stock 7300GT that came with the computer works fine. It looks like it is a bad graphics card and will require returning. I was wondering whether this is a common problem and if anybody else has experienced it?