i am running a Ti 4400 drivers 66.93 2.4GHZ and was having the lockup the screen bug which usually rebooted the computer on its own. I had set my screen resolution to 1024x768 even though the game recommended 800x600. After changing to 800x600 i haven't had any further problems YET. I am just leaving the Ithorian compound which caused 3 reboots alone also found in 1024 screen had a lot of black squares scattered on screen , in 800 mode they were gone. Hope this helps.
I must admit i wont be purchasing anymore Obsidian games in the future until they have been out long enough so i can see how buggy they are. i.e. when they are in the bargain bins.
