OCS 2007 R2 Group Chat Updates (CU5)
In case you are not already aware, the latest set of GC updates for OCS 2007 R2 have been released:
Office Communications Server 2007 R2, Group Chat Server
https://support.microsoft.com/kb/980042
Office Communications Server 2007 R2, Group Chat Client
https://support.microsoft.com/kb/980043
Office Communications Server 2007 R2, Group Chat Admin Tool
https://support.microsoft.com/kb/982128
Office Communications Server 2007 R2, Group Chat Server SDK