Hello, I just bought a quad core mac pro with an ATI Radeon HD 4870 graphics card. I installed bootcamp with Windows XP Service pack 2 onto the computer and went to install Company of Heroes Tales of Valor onto it and it said that it could not be installed because I was missing "Pixel Shading". I was under the assumption that the Radeon 4870 had pixel shading on it? Is there something I have to download or am I just out of luck? I know this is a freakishly specific question but any help would be greatly appreciated!