When I first installed and patched I had this problem. I was getting a conflict with my printer. I turned off everything running in the background and reloaded and Civ3 worked okay.
Once that happened, I can now run anything else I want without a text problem, it was just on the first game after the install that I had the problem.
You will also want to enable font smoothing and do a search on fonts here and at Apolyton for some other problems and solutions.