I have a client running a server 2012 with several shared folders/drives filled with various Office documents (Word and Excel). The issue is, when a user tries to open a file, they receive a prompt stating the file is locked for editing because it is open by a particular user. That user does not have the file open, but he did create them originally.
This prevents users from knowing who has a file open to ask them to close it or go close it for them in cases of an unattended workstation.
They are using Office 2007. I have located a possible fix for Excel at http://support.microsoft.com/kb/2598133
but it does not explain the behavor with Word.