Cannot connect Office Communicator 2007 R2 to Office Communications Server 2007
Summary:
You cannot connect to an Office Communications Server 2007 using an Office Communicator 2007 R2 client.
Details:
There are architectural changes introduced into Office Communicator 2007 R2 that are only compatible with Office Communications Server 2007 R2.
Workaround:
On Office Communications Server 2007, you can select to block Office Communicator 2007 R2 clients from connecting.