RT73 ok, if it doesnt startup when you boot into leopard, try boot in force mode, to test ok? it should popup when you boot in
About the Video, this is what you need to do, install 9f23 version, i will ask you to install efi studio, installed with efi...
After installation Efi studio will show up, then select display, then select your video card, which is 8600 GT 512mb if is like mine then click Add Device, Click Write to com.apple.boot.plist and reboot
You should get QE/CI now, you can always check if you have fully support in system profile
You can always add me to MSN