our application is running on the tomcat 4.0.x and jboss 3.2.x. now I try to update jboss to the 4.0.x. first all, I got the hashcode exception. so I update jbossall-client.jar in web-inf\lib of the application on tomcat by the new jboss client\jbossall-client.jar. then, tomcat can not be started well, throws the org.apache.jasper.servlet.JspServlet is not a Servlet exception. I also update the jasper jar file. then throw other exception. I think i mess up. can some one help me and tell me how to do the upgrade of jboss, therefore old tomcat still can talk to the new jboss server.