I have a Mac Pro model macpro1.1, or A1188, with an ATI Radeon X1900 graphics chip set. Blizzard (World of Warcraft) informs me that this does not meet their minimum hardware requirements. Can anybody recommend an upgrade card? Blizzard wants at minimum an nVidia geforce 9600m gt or ATI radeon hd4670. Apple store people assure me that the nVidia card will not run on my machine. Preliminary investigation of ATI's website failed to reveal any information on Mac support.