If I don't rember wrong the Europe version hasen't been reales yet. That mean the only patch out there is for North American that's using SecuRom.
And the Europe version using the SafeDisc version.
How ever. Don't download the patch on MegaGames. Always go to offical homepage. Like
www.civ3.com
And U are a European click on UK in top of the page. Then U are going in to UK version of the page. There is only 1.14F patch out there. So that's mean the 1.21F hasen't been releas.
To change it back, just uninstall the 1.21F patch And maybe U need to reinstall the game.