according to the user "orpsmorps" in the forums, the problem's solved and the apps should be launching correctly now.

I'm still downloading, however =(

anyway, have fun playing!

according to "dbroudy" in the steam forums, it's downloading an update now.

I still didn't finish downloadint the game at all :(

anyway, I hope, the update will make the game(s) playable for you!

Seems like we have another problem. The game can now be downloaded by everyone, but nobody is able to start it anymore.

I didn't download it yet, but according to the forums, this affects just about everyone who purchased Civilization IV.

Valve didn't confirm this issue yet.

If you have a temporary solution for this problem, please post it as a comment here.

Previous PC Owners of Civilization IV Games on Steam Get Mac Version
Announcement - Valve16:54
Yesterday when we shipped Steam on the Mac, previous owners of the PC Steam version of Sid Meier's Civilization IV, Civilization IV: Beyond the Sword, Civilization IV: Warlords, Sid Meier's Civilization IV: Colonization, or Sid Meier's Civilization IV: The Complete Edition did not have access to their games when logging in on a Mac.

But as of now, upon logging into Steam, those owners will have access to the Mac version of their games, right in their Steam library.

source: http://store.steampowered.com/news/3827/

Civilization IV can now be downloaded by anybody who bought the game. No matter if it was purchased before or after the release of Steam for Mac. restart your steam client in order to download the game. Thanks to Mikkel for mentioning that.

Since the problem is solved, we could turn our little community into a ... well, civ for mac community. Anyone wants to play a few turns? :)

O and by the way, since you've saved some money not having to re-buy these games, feel free to spend some if it on http://www.paythegame.net, financing my education :>