Article ID: 2545864 - View products that this article applies to.
When two instances of a Microsoft Office Communications Server 2007 R2, Group Chat client are started at the same time, a race condition occurs. Additionally, this causes the Office Communications Server 2007 R2, Group Chat client to crash.
To resolve this issue, install the following cumulative update:
(http://support.microsoft.com/kb/2549043/ )Description of the update for the Office Communications Server 2007 R2 Group Chat client: June, 2011
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.