How to access all functions on an object that is instantiated remotely using a Transparent proxy though System.Activator.GetObject()

Question

I am accessing an object remotely using a Transparent Proxy. The object, named TaskSchedulerServiceManager (which implements MarshalByRefObject), has a method on it named GetMachineName, which should simply return the NetBios name assigned to the machine the actual object is running on.

public class TaskSchedulerServiceManager : MarshalByRefObject
{        public string GetMachineName()
    {
        log.Write(log.Level.Debug, "GetMachineName()", eventSource); 
        return Environment.MachineName.ToUpper(); // <- line that throws exception
    }
}

The TransparentProxy is instantiated using System.Activator.GetObject() in the following code:

    private static TaskSchedulerServiceManager
          GetServerManager(TaskSchedulerServer svr)
    {
        svr.RegisterChannel(); // see below
        var url = "tcp://" + svr.ServerName + ":" +
                   svr.TcpPort + "/" + svr.ManagerUri;
        return (TaskSchedulerServiceManager)Activator.GetObject(
                    typeof(TaskSchedulerServiceManager), url);
    }

    public void RegisterChannel()
    {
        UnRegisterChannel();
        IDictionary propBag = new Hashtable();
        propBag["port"] = TcpPort;
        propBag["name"] = KeyID;
        propBag["connectionTimeout"] = 1000;
        if (SecurityMode == RemSecMode.Identify)
        {
            propBag["secure"] = true;
            propBag["tokenImpersonationLevel"] =
                TokenImpersonationLevel.Identification;
            propBag["useDefaultCredentials"] = true;
        }
        if (ChannelServices.RegisteredChannels.Any(
            chn => chn.ChannelName == KeyID &&
            chn is TcpClientChannel)) return;
        // ------------------------------------------
        tcpCh = new TcpClientChannel(propBag, null);
        if (!ChannelServices.RegisteredChannels.Contains(tcpCh))
            ChannelServices.RegisterChannel(tcpCh, false);
    }

Now in my client code I am trying to clal GetMachineName on the transparentProxy as shown in the first snippet above. When I do a System.Runtime.Remoting.RemotingException is thrown:

System.Runtime.Remoting.RemotingException: 'The method 'GetMachineName' was not found on the interface/type 'CoP.Enterprise.Scheduler.TaskSchedulerServiceManager, CoP.Enterprise.TaskScheduler, Version=0.31.200.31000, Culture=neutral, PublicKeyToken=null'.'

Even though intellisense shopws that the method exists on the object and the compiler does not throw a compile error.

What is up with this?