You are an agent of a Response Group Service (RGS) group, in which the agent participation policy is Informal and the routing method is Serial.
You have Microsoft Office Communicator 2007 R2 paired with Lync 2010 Phone Edition.
Someone calls the RGS group.
The call is routed to you.
You try to answer the call by using Office Communicator 2007 R2.
In this scenario, a fatal exception occurs.
To fix this problem, install the following cumulative update:
2291453 Description of the cumulative update package for Communicator 2007 R2: November 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.