Same here (MacOSX 10.6.8, Steam client app built Nov 12 2011 09:36:52, API v012, package version 1320171134).
I noticed that while starting up the game (fm2012), it fails to start file
~/Library/Application Support/Steam/SteamApps/common/football manager 2012/fm.app/Contents/MacOS/fm
this file...