Due to a bug that slipped through, Firaxis has put the patch on hold. If you installed it, you can uninstall the patch by using the uninstall option from the Civ4 CD’s startup program.
Luckily I’ve been too busy: no time to play Civ 4.
Update: Patch 1.09 (23 MB) fixes the Fog of War and other T&L problems, even for my mere Intel GPM card. Civ IV does come up with a message saying that my configuration is actually below ‘requirements’ but allows me to continue playing. Never had that message before, either.