I'm running an AMD 3800x2, 2 GB DDR 400Mhz RAM, 2 GeForce 6800's in SLI on an NForce4 chipset. I've played all previous releases of Galactic Civ II without any errors crashes. As soon as I rebooted my machine after installing 1.11 my machine blue-screened with the infamous "n4_disp infinite loop" error, which many NVidia users have experienced over the years for a variety of reasons, but basically it means you've got a problem with your video driver. I booted to safe mode and reinstalled the driver and everything started up fine. As soon as I re-enabled SLI, my machine crashed with the same error. I've tried many things to fix this that I've found suggested on the web, but every time I re-enable SLI it crashes. I believe that a registry key (or keys) related to the "memory optimizations" are to blame, but I don't know which keys were modified or what to change them back to. Anyone out there know?