Article ID: 968690 - View products that this article applies to.
In a group IM session in Office Communicator 2007 R2, User A sends User B an instant message (IM). User B receives the IM successufly. However, User A still gets a failure-to-deliver message that states that his IM has not been received by User B.
This issue occurs because the 202 Accept message and the Notify message that are sent for the IM are received in reverse order.
To resolve this issue, apply the following update:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.