I am unable to use single sign on with Matrix Silverlight. When I put _xmppClient.UseSso = true; in my code it tells me there is no extension method. What am I missing?
SSO using Kerberos is not supported in the Silverlight version. For Kerberos API calls to the SSPI API are required.
In theory this would probably be possible when using Silverlight 5, running in OOB mode with elevated permissions.