directx problem with cod ghosts

I loaded Ghosts on my Mac computer running windows 7 through Bootcamp. The game installs okay and shows in Steam but I cannot play due to "irrecovoverable error with directx". I have uninstalled and re-installed the game and run the Directx diagnostic which states all is okay with Directx. Other cod games run okay. So, at a loss right now, any help with this would be really appreciated. Thanks.