I've been struggling with this for a few days now, and hopeful that someone on here has a simple solution. I've got the AMD Radeon HD 7800 series on a Windows 7 Pro (x64) machine. All 6 monitors are the same (Asus VS248, 24") and connected via HDMI-to-Mini Displayport cables. At most, I can get the AMD Catalyst Control Center to Enable 5 of the 6 monitors. When I try to extend the desktop to include the 6th monitor, I get a message "To extend the desktop, a desktop or display must be disabled".
Also if I try to create a new display group, the maximum number of displays it will let me include in the group is 5.
I know that the 6th monitor works as I am able to exchange it for one of the other 5 monitors. Before upgrading the driver to the latest version, I was able to have all 6 monitors active and utilized.
Has anyone run into this before? Any suggestions?