The last dialed telephone number for a contact changes to "Communicator Call" after you start Communicator 2007 R2 or Communicator 2007

After you restart Microsoft Office Communicator 2007 R2 or restart Microsoft Office Communicator 2007, the last dialed telephone number of a contact is set to Communicator Call. This occurs even if another telephone number for this contact was dialed in the last Communicator session.

Additionally, you have to manually select one of the other available telephone numbers for that contact because Communicator Call is not available.

This issue occurs because Communicator cannot keep the default telephone number, which is the last dialed telephone number, for the contact when the registry entry is set to 4.

Note If the registry entry is set to 4, no Communicator calls are enabled. This registry entry is located under the following registry subkey: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Communicator

To resolve this problem, install one of the following update packages depending on the version of Communicator that you use: 

• 2028888  (http://support.microsoft.com/kb/2028888/ ) Description of the cumulative update package for Communicator 2007 R2: July 2010
• 2028885  (http://support.microsoft.com/kb/2028885/ ) Description of the cumulative update package for Communicator 2007: July 2010

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.