I recently installed a ATI 5770 in my 2008 MacPro. When I installed it I was running 10.6.5 and recently installed 10.6.6. I have been reading when you upgrade a early 2008 macpro be sure to install the Snow Leopard update. I downloaded the standalone update and it will not allow me to install it. I checked the software update log and it was not installed when I was running the 8800GT. Do I need to try to hack a install or was it only for 10.6.4?