Its happened to me twice now. Im early on in the game. Ive researched one or two techs but then when I go into the research screen the monitor goes black. I can still hear the music and I believe the game is still running as if I press the escape key I can hear the music change. I only get a few turns per play before having to kill the game. I was a beta tester and I did not download a fresh copy of the game on release (dont think I should have to).
