Article ID: 943019 - View products that this article applies to.
A computer is running the Communicator Web Access Server role in Microsoft Office Communicator 2007. If the Communicator Web Access Server role must end an incoming instant message invitation that was received in a callback event in a collaboration session, the thread that contains the instant message invitation may wait indefinitely.
This problem may occur if the following conditions are true:
To resolve this problem, apply the Communications Server 2007 update package for the Unified Communications Managed API v1.0 Redistribution that is dated December 17, 2007.
For more information about the update package, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/944285/ )Description of the Communications Server 2007 update package for the Unified Communications Managed API v1.0 Redistribution: December 17, 2007
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.