Security Exception Running DIME Sample

While running the MS Dime Sample application, I receive the following exception:

--- begin exception message ---
A first chance exception of type 'System.Security.SecurityException' occurred in mscorlib.dll

Additional information: Hash for the assembly cannot be generated.
--- end exception message ---

This occurs as soon as I obtain a reference to the Web Service.  I've also created a new Test Web Service with similar functionality and receive the same exception exception in the Proxy Constructor:

        public JoesDimeWebServiceTest() {
            this.Url = "http://localhost/JoesDimeWebServiceTest/JoesDimeWebServiceTest.asmx";
        }

Joe