OK so weird issue here. I have previously been running 6 screens off of 3 of the older ATI firepro graphics cards but they had a problem with the heat sink getting too hot and warping the PCB resulting in total failure of the card, to replace my three dead cards I purchased a new-type ATI firepro with the newer heat sink design. I'm only using one at the moment to make sure they've fixed the problem before I waste more money on 2 more cards but this is where things start to get weird.
The Firepro's only have one port on them, they connect to two monitors via a splitter cable going from the one port to two DVI connectors for the screens. When I plug two identical monitors in via their DVI inputs not matter what I do windows and Catalyst will only detect one screen. However if I use the VGA input on one of the screens with a VGA -> DVI adaptor to plug it in to the card it works fine. This confuses me greatly.
I'm currently using the ATI Firepro 2270 Graphics card with identical DELL U2311H screens. I can post the rest of the system spec as well if needed but I wouldn't have thought it would make much difference as it had no problem handling 6 screens before the graphics cards failed. Naturally both catalyst and ATI drivers are the most current version. ATI tech support has been absolutely zero help, they seemed to get stumped as soon as I verified that both screens were plugged in and connected properly.
Anyone have any ideas?