We have 2013.2.0582
Sometimes it takes us a little bit to update to the latest version. I will try this again when we get the latest.
However, to reproduce this:
Go into Control Panel -> Appearance and Personalization -> Display and set to "Medium - 125%" and restart the machine
Start the application after the restart and open the backstage. When you resize the window the scroll bar doesn't work correctly and not all of the buttons/tabs are visible to the user.
Thanks.