I've seen a couple posts regarding this type of error but their resolutions haven't solved our issue though. We're testing our install using a very simple example EJB. The client looks like this (not complete code):
 // preparing properties for constructing an InitialContext object
 Properties properties = new Properties();
 properties.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
 properties.put(Context.PROVIDER_URL, "jnp://69.57.141.196:1099");
 try {
 // Get an initial context
 InitialContext jndiContext = new InitialContext(properties);
 System.out.println("Got context");
 // Get a reference to the Bean
 Object ref = jndiContext.lookup("StringProcessor");
 System.out.println("Got reference");
 // Get a reference from this to the Bean's Home interface
 StringProcessorHome home = (StringProcessorHome)
 PortableRemoteObject.narrow (ref, StringProcessorHome.class);
 System.out.println("Got home");
 // Create an Adder object from the Home interface
 StringProcessor sp = home.create();