Article ID: 976048
You start Microsoft Office Communicator 2007 R2. However, when you log off, restart, or shut down the computer, you receive the following error message:
Additionally, the error message blocks the logoff process or the shut down process for about 20 seconds.
End Program – Communicator
To resolve this issue, apply the following update:
(http://support.microsoft.com/kb/972884/ )Description of the update for Communicator 2007 R2: Oct 2009