Article ID: 2464049 - View products that this article applies to.
Microsoft Office Communications Server 2007 R2 eXtensible Messaging and Presence Protocol (XMPP) Gateway becomes unresponsive intermittently.
This issue occurs because a NULLReferenceException exception occurs when Office Communications Server 2007 R2 XMPP Gateway tries to process presence data that do not have a To header.
To resolve this problem, install the following cumulative update:
(http://support.microsoft.com/kb/2404570/ )Description of the update for Office Communications Server 2007 R2 XMPP Gateway: November 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.