In OS X Mountain Lion (10.8.2) there is a very annoying bug which prevents “Show in Finder” (or “Reveal in Finder“, “Open in Finder“) functionality (usually a menu item) from working in many applications including TextMate, TotalFinder, Transmit, The Unarchiver, Postbox, iPhoto.
Relaunching Finder or the affected application does not help. What helps is logging out/logging in or running the following command in Terminal to kill the Apple Events daemon:
sudo killall -KILL appleeventsd
Terminal will ask you for your password. In case you don’t have a password for your OS X user account, you need to set it temporarily in System Preferences > Users & Groups.
Alternatively, you can use Activity Monitor to kill
The bug appears in other situations which involve communication between applications. For example, drag-n-drop stops working in Name Mangler.
This is clearly a bug on Apple’s side and it will be probably fixed in the next update.
Other information on the issue: