I have a WCF service multiple UIs consume. When the user is unable to access the database, I get Unauthorised exception from the DB. I don\'t catch the exception on the server
See the following link which talks about how WCF clients should catch faults/exceptions and potential problems you may run into with the 'using' statement in C#:
http://msdn.microsoft.com/en-us/library/aa355056.aspx
Baiscally you need to call Abort() on your client proxy. This will immediately set the state of the proxy to Closed.