If that is true and you are playing the demo, then if you are from Gamespot which suspended me for giving out these other forums there all the time for all the question when I was only trying to help, then it is possible that all of that was fixed in the patches that came out for the game after the demo was probably made.
I know Gamespot has a forum, but really the amount of new people having problems with the hardware of the computer may not actually realize that there are places such as CivFanatics on the Internet. Unfortunately for Gamespot then, the forum for Civ IV is now deleted by me. I just started up a thread to state where to find help like over at CivFanatics and another place, I just forget to mention that it was mainly for the hardware help, although here is the place where all the help and files and Mods and Scenarios and Game of the Month along with Apolyton where new players can see the support Civilization games get in this World.
So much for that then! I delete Gamespot myself.