Lewis
As we depreciated Server 2003 AD R2 integration with Jabber 10.5 we haven't carried out any test or validation, so are unable to advise if the integration would be successful. As support for this has been depreciated, it would not be supported by Cisco with a Jabber 10.5 live deployment.
Microsoft's Mainstream support for this AD solution ended in 2010 and our integration efforts have now shifted to newer products based on customer demand.
You can either continue to run an older version of Jabber which does support this integration, or you'll need to plan for an AD product update (I appreciate that's a major undertaking.)
thanks, Damien