[MSO 2010] "Save in Nuxeo" is displayed after document is closed

Steps to reproduce:

1. Click on Live Edit icon to edit a document.
   The document opens in MS Office.
2. Edit the document.
3. Close MS Office.
   A window is displayed, to save temp document.
4. Don't save temp document.
   MS Office closes, and then the "Save in Nuxeo" window is displayed.
   As a consequence, modifications are not saved in Nuxeo.