There was an update recently. Steam should recognize that automatically, but some users reported issues. You should double check:
Goto Steam, MyGames. Right click on the title in question, select properties. Check the update Tab. Make sure "always keep updated" or whatever its titled in the english version is selected.
Check that for all Simbin titles you own.
Ingame in the main menu it should say 1.2.1.2 at the bottom.
If your game is all up to date and you still have issues also check
this thread.
There are some problems regarding the updater at the moment.
