Ran into the strangest problem today. One of our users Sent Items box was renamed to one of her contacts names. Since there is no way I know of to rename the Sent Items box, I was stumped.
Finally found the answer.
Open a command prompt as an administrator
Type "%ProgramFiles%\Microsoft Office\Office14\Outlook.exe" /resetfoldernames
That will launch Outlook and reset the folder names.
Hope this helps someone out there in the future.