Mountain Lion Title Bar Truncation With OSX Mountain Lion (10.8.2) there is a UI problem. 

Calendar + Reminder +  Sticky Note apps have truncated title text

If i login as a guest they are correct. There is clearly a preference somewhere which is causing this but I've got no idea how to fix it.
The similarities between these three applications is that they all show "Updating..." in the title bar when sending/receiving data. Maybe something related to sync services or Calendar Agent? It might help to reset sync services.

Issues that are only occurring within your user account (and not others) are most likely related to preferences or other data inside of that account. A great place to start is the ~/Library/Preferences folder. Performing a split-half search on the contents of that directory is a good way to attack the issues. If the problem doesn't lie within the Preferences folder, there's a good chance that it's in ~/Library somewhere (Calendars?).

If you're lucky, the upgrade to Mavericks won't use the same functionality (i.e., won't read the corrupt preferences)...However, you may still experience the issues in that OS if you install over the top of your current user environment.