I've got a setup that is running 2 ATI 5850s with dual monitors. I tried to add a 3rd monitor but when I do, I get the error message "to extend the desktop, a desktop or display must be disabled". Basically it's only letting me run 2 at a time, any 2 works.
I've got 2 monitors using the DVI??? (whatever the white port is) and one using HDMI. I have tried running all 3 from one card, and I've tried doing various combinations using both cards and I can only get 2 monitors to run.
Not doing any crazy 3d stuff, I just want 3 monitors for my desktop. Any ideas?