Picture simply becomes black or a black triangle

I have the same problem, I have two NVIDIA GeForce 7300GT on a new Mac Pro with Leopard and Aperture 1.5.6. When I have three monitors plugged in, Aperture does not display many pictures properly, on the alternate monitor it frequently comes up blank. On the main monitor, when I go to Full screen mode (press F), many photos look look completely corrupted. I figured out that the problem is a result of two video cards. I have the same problem when only using two monitors, if the monitors are plugged into different video cards. If the two monitors are plugged into the same card, it works fine (when their are only two monitors, not three).

Yes, Aperture is known not to work right with two graphics cards or more than two monitors.

Do you know if this is documented anywhere on Apple's site? I was on the phone with Aperture support and the person I spoke with said Aperture works with two monitors (which I knew), but he couldn't find anything about it not working with two video cards.

Do you know if there is a way to get aperture to just ignore the 3rd monitor. I want to use aperture on two monitors, and have other stuff on the 3rd like my browser or email. But if I even have 3 monitors plugged into the computer aperture doesn't work.

--Scott

There's an oblique reference to numbers of graphics cards here:

http://docs.info.apple.com/article.html?artnum=303215

(I just noticed that the tech specs do say 'one of the following graphics cards' in both minimum and recommended configurations, but I think that's coincidence rather than subtle specification.)

I think the 3-display problem has merely been noted (and reported) by some people in this forum who have more than two displays.