Java RMI Server/Registry error on AS/400 -- JAVA400-L

I am having an issue (java.rmi.NoSuchObjectException: no
such object in table) running RMI on an AS/400 that I haven't seen
elsewhere.
I am going to include source code for a test server that I have been
running.

I am submitting the following two commands with a SBMJOB of a STRQSH
command:

rmiregistry

java -Djava.rmi.server.hostname=[ip address of firewall]
RMITestServer.RMIServer

The server works with no problems for a while, but then after an
indetermined amount of time/number of uses I get the following exception
when hitting it with my test client: java.rmi.NoSuchObjectException: no
such object in table

I am guessing this is an AS/400 issue as I have never seen this, but I am
not sure. The jobs have been set to a RUN PRIORITY of 20 so that they don't
get overrun by interactive jobs.

This is very troubling, I can't figure out what is going on here - please
assist if you can!

Here is the server code:

package RMIServerTest;

import java.rmi.*;

public interface RMIServerInterface extends Remote
{
public TestReturnClassInterface getTestReturnClass(String version) throws
RemoteException;
public String testServer(String incomingText) throws RemoteException;
}

package RMIServerTest;

import java.rmi.*;
import java.rmi.server.*;
import java.rmi.registry.*;
import java.io.*;
import java.util.*;

public class RMIServer extends UnicastRemoteObject implements
RMIServerInterface
{
/**
* RMIServer constructor comment.
*/
public RMIServer() throws RemoteException
{
super();
}
public TestReturnClassInterface getTestReturnClass(String version) throws
RemoteException
{
return new TestReturnClass();
}
public static void main(String arg[])
{
try
{
   RMISocketFactory.setSocketFactory(new FirewallSocketFactory());
   System.setSecurityManager(new RMISecurityManager());
   System.out.println("Initializing Server...");

   RMIServer rmiServer = new RMIServer();
   Naming.rebind("RMIServer",rmiServer);
   System.out.println("Server Ready...");

   // Take out startup garbage now
   System.gc();
   System.runFinalization();
}
catch (Exception e)
{
    System.out.println("Exception occured: " + e.getMessage());
    e.printStackTrace();
    System.exit(0);
}
   System.out.println("Server Ready...");
}
public String testServer(String incomingText) throws RemoteException
{
System.out.println("Client testServer() invocation: "+incomingText);
return "Text received from Server class: "+incomingText;
}
}

package RMIServerTest;

import java.net.*;
import java.io.*;
import java.rmi.server.*;

public class FirewallSocketFactory extends RMISocketFactory
{
/**
* SSLSocketFactory constructor comment.
*/
public FirewallSocketFactory() {
super();
}
public ServerSocket createServerSocket(int port) throws IOException
   {
if (port==0)
{
                        file://Set static port for Firewall
     return new ServerSocket(1098);
}
else
{
     return new ServerSocket(port);
}
   }
public Socket createSocket(String host, int port) throws IOException
   {
    return new Socket(host,port);
   }
}

package RMIServerTest;

import java.rmi.*;

public interface TestReturnClassInterface extends Remote
{
public String testReturnClass(String incomingText) throws RemoteException;
}

package RMIServerTest;

import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class TestReturnClass extends UnicastRemoteObject implements
TestReturnClassInterface
{

public TestReturnClass() throws RemoteException
{
super();
}
public String testReturnClass(String incomingText) throws RemoteException
{
System.out.println("Client testReturnClass() invocation: "+incomingText);
return "Text received from Return class: "+incomingText;
}
}

And here is the client I am using:

package RMIServerClient;

import java.rmi.*;
import RMIServerTest.*;

public class RMIClient
{
public RMIClient()
{
super();
}
public static void main(String arg[])
{
try
{
   RMIServerInterface
rmiServer=(RMIServerInterface)Naming.lookup("rmi://12.10.67.226/RMIServer");
   TestReturnClassInterface
testReturnClass=rmiServer.getTestReturnClass("1");
   System.out.println(rmiServer.testServer("test of Server class"));
    System.out.println(testReturnClass.testReturnClass("test of Return
class"));
}
catch (Exception e)
{
    System.out.println("Exiting..." + e);
    System.exit(0);
}
}
}