Is there a way to have the guest (XP or VIsta) take up the full screen with the apple 30" display? I just got one and when making the guest go full-screen it only covers the middle portion of the screen (not full). The max I can make it is 1600x1200 running in non-full screen mode. It would be great to be able to have the guest use all of the real estate in the 30 inch display.