求救!!为什么在was发布应用成功,可是在运行时,总是异常找不到WEB-INF的lib包里的类??

各位大佬：
我用was自带的应用程序组装工具将我的应用系统打包成功后，发布到was下面，并且发

布也提示成功！ index.jsp首页也进去了，但是登陆时，后台提示我有个类不能访问？
具体的异常如下：

[04-1-17 14:04:15:016 CST] 7fce740f WebGroup I SRVE0180I: [Struts Example Application] [/changqing] [Servlet.LOG]: /jsp/message/messageList.jsp: init
[04-1-17 14:04:15:047 CST] 7fce740f WebGroup E SRVE0026E: ［Servlet 错误］－［cn.com.xinli.mdis.util.JDomUtil tried to access method org/jdom/Document.<init>()V］：java.lang.IllegalAccessError: cn.com.xinli.mdis.util.JDomUtil tried to access method org/jdom/Document.<init>()V
at cn.com.xinli.mdis.util.JDomUtil.createDocument(JDomUtil.java:47)
at cn.com.xinli.mdis.tag.message.MessageListTag.doTag(MessageListTag.java:37)
at cn.com.xinli.mdis.tag.WebAppBaseTag.doStartTag(WebAppBaseTag.java:74)
at org.apache.jsp._messageList._jspService(_messageList.java:82)
at com.ibm.ws.webcontainer.jsp.runtime.HttpJspBase.service(HttpJspBase.java:89)
at javax.servlet.http.HttpServlet.service(HttpServlet.java(Compiled Code))
at com.ibm.ws.webcontainer.jsp.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:344)
at com.ibm.ws.webcontainer.jsp.servlet.JspServlet.serviceJspFile(JspServlet.java:598)
at com.ibm.ws.webcontainer.jsp.servlet.JspServlet.service(JspServlet.java:696)
at javax.servlet.http.HttpServlet.service(HttpServlet.java(Compiled Code))
at com.ibm.ws.webcontainer.servlet.StrictServletInstance.doService(StrictServletInstance.java(Compiled Code))
at com.ibm.ws.webcontainer.servlet.StrictLifecycleServlet._service(StrictLifecycleServlet.java(Compiled Code))
at com.ibm.ws.webcontainer.servlet.ServicingServletState.service(StrictLifecycleServlet.java:333)
at com.ibm.ws.webcontainer.servlet.StrictLifecycleServlet.service(StrictLifecycleServlet.java(Inlined Compiled Code))
a

messageList.jsp就是登录时要调用的，他里面的tag用到了DomUtil.class这个类，org/jdom/Document东西是我 ..\WEB-INF\lib路径里的jdom.jar包。

为什么会出现这个问题呢？ 请各位大佬帮小妹分析一下好吗？
谢谢了。