No more GMA900 when FX5700 installed

[cyrana]

Well I got an FX5700LE PCI card so I could do dual displays (I needed dsub, and no way to get it on the 2nd display when using an ADD2-N card). If I set the GMA900 to be the primary display in BIOS it works fine, but then OS X won't detect the 5700 if I hit the detect displays button in display preferences. If I set the 5700 to primary, it works fine, but then the computer crashes and the monitor plugged into the onboard gets all goofy when I hit detect displays.