More good news: The Civ IV patch is supposed to come out really soon. Says someone at Civ 4:
Some of the highlights include multiple AI improvements and tweaks, worker behavior tweaks, MANY game play improvements (ex Animal Husbandry reveals horses), promotion tweaks, a softer pillage sound (requested by many, many people), fixed diplomatic exploits (gold for gold, peace treaty exploit), multiplayer tweaks (Hot seat, Lobby, etc.), memory, caching and performance improvements, etc. There were also a number of video card specific fixes.
Let’s hope they’re the right fixes. And if they have fixed the black terrain bug, I expect them to give a full (technical) explanation. This is obviously the page that is going to be watch by many Civ4 players.