Problem: In Outlook (Office 2013) when a calendar is printed, appointments are printed twice.
Solution: Apply MS Hotfix KB2817468 to fix.
Important Note: Microsoft warn that after this update is installed, Outlook may crash when trying to open encrypted email messages. If you experience this, the only fix is to uninstall the update. Microsoft say they are researching the problem and will post more information in the KB article when available.
I personally haven’t had this problem outlined by Microsoft, and have installed it across a number of machines. Many of the end-users I deal with don’t use encrypted email messages however.