应为NamingException,得到NoSuchObjectException

我在Weblogic 11g上运行Java 6。

我正在处理一个Web服务项目,该项目使用EJB与数据库进行通信。目前我正在处理错误,因此我尝试在调用web服务之前取消部署EJB。我的EJBClientHelper类如下所示:

package mypackage.elkom.utils;

import java.io.Serializable;
import java.util.Properties;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

import mypackage.elkom.ejb.beans.session.remote.ElkomRemote;

public class EJBClientHelper implements Serializable {

  /**
   * 
   */
  private static final long serialVersionUID = 1L;

  private ElkomRemote elkomRemote;

  private static final String ELKOM_JNDI =   "ElkomBean#mypackage.ejb.beans.session.remote.ElkomRemote";

  private Context ctx;

  private void prepareEjb3Connection() throws PropsFileException, NamingException {
      // Here's code for getting the ejbProviderURL from propsfile //
      props.put("java.naming.factory.initial", weblogic.jndi.WLInitialContextFactory");
      props.put("java.naming.provider.url",ejbProviderURL);
      ctx = new InitialContext(props);

 }

  public void setElkomRemote(ElkomRemote elkomRemote) {
    this.elkomRemote = elkomRemote;
  }

  public ElkomRemote getElkomRemote() throws NamingException, PropsFileException {
    prepareEjb3Connection();
    if(elkomRemote == null) {
    elkomRemote = (ElkomRemote)ctx.lookup(ELKOM_JNDI);
   }
   return elkomRemote;
  }

}

但是,当我使用getElkomRemote()时;我收到的消息不是NamingException:

SEVERE: The object identified by: '678' could not be found.  Either it was has not been exported or it has been collected by the distributed garbage collector.; 
nested exception is: java.rmi.NoSuchObjectException: The object identified by: '678' could not be found.  
Either it was has not been exported or it has been collected by the distributed garbage collector.
javax.ejb.EJBException: The object identified by: '678' could not be found.  Either it was has not been exported or it has been collected by the distributed garbage collector.; 
nested exception is: java.rmi.NoSuchObjectException: The object identified by: '678' could not be found.  
Either it was has not been exported or it has been collected by the distributed garbage collector.
java.rmi.NoSuchObjectException: The object identified by: '678' could not be found.  Either it was has not been exported or it has been collected by the distributed garbage collector.

有人知道我为什么收到这个消息而不是NamingException吗?也许该怎么解决呢?