EJB calls across app. servers

If I attempt to lookup a remote (on a different application server) EJB within a servlet, I am able to successfully locate and create() the EJB. If I attempt to lookup a remote EJB from within an EJB, it fails***. If I attempt to lookup the same EJB remotely, but within the same application server, it succeeds.
The failure occurs with a specific installation of WebSphere - that is, it succeeds when I deploy the EJB on another machine altogether. This seems to indicate a problem with the particular remote WebSphere installation, or a network issue with that particular machine.

***The failure is in the call to create() the EJB:

java.rmi.RemoteException: CORBA TRANSIENT 0x4942f301 No; nested exception is: org.omg.CORBA.TRANSIENT: 
Trace from server: 1198777258 at host <omitted> >>
org.omg.CORBA.TRANSIENT: Connection refused:host=localhost,port=4228  minor code: 1229124353  completed: No
        at com.ibm.CORBA.transport.TransportConnectionBase.connect(TransportConnectionBase.java:450)
        at com.ibm.ws.orbimpl.transport.WSTransport.getConnection(Unknown Source)
at com.ibm.CORBA.transport.TransportBase.getConnection(TransportBase.java:158)
at com.ibm.rmi.iiop.TransportManager.get(TransportManager.java:83)
at com.ibm.rmi.iiop.GIOPImpl.locate(GIOPImpl.java:174)
at com.ibm.rmi.corba.ClientDelegate._createRequest(ClientDelegate.java:1927)
at com.ibm.rmi.corba.ClientDelegate.createRequest(ClientDelegate.java:1235)
at com.ibm.rmi.corba.ClientDelegate.createRequest(ClientDelegate.java:1168)
at com.ibm.rmi.corba.ClientDelegate.request(ClientDelegate.java:1830)
at org.omg.CORBA.portable.ObjectImpl._request(ObjectImpl.java:428)
at org.omg.CosTransactions._CoordinatorStub.hash_transaction(Unknown Source)
at com.ibm.ejs.jts.jts.CoordinatorImpl$Holder.<init>(CoordinatorImpl.java:533)
at com.ibm.ejs.jts.jts.CoordinatorImpl.get(CoordinatorImpl.java:502)
at com.ibm.ejs.jts.jts.ControlSet.received_request(ControlSet.java:1102)
at com.ibm.ejs.jts.jts.ServerInterceptor.receive_request(ServerInterceptor.java:321)
at com.ibm.rmi.pi.InterceptorManager.iterateReceiveRequest(InterceptorManager.java:739)
at com.ibm.CORBA.iiop.ServerDelegate.dispatchInvokeHandler(ServerDelegate.java:604)
at com.ibm.CORBA.iiop.ServerDelegate.dispatch(ServerDelegate.java:468)
at com.ibm.rmi.iiop.ORB.process(ORB.java:396)
at com.ibm.CORBA.iiop.ORB.process(ORB.java:1608)
at com.ibm.rmi.iiop.Connection.doWork(Connection.java:2164)
at com.ibm.rmi.iiop.WorkUnitImpl.doWork(WorkUnitImpl.java:63)
at com.ibm.ejs.oa.pool.PooledThread.run(ThreadPool.java:95)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:593)
<<  END server: 1198777258 at host <omitted>

Any suggestions regarding how to have this remote EJB call succeed from within an EJB container are most appreciated.