GWT ASync call back problem

I'm trying to learn GWT and I have been following the tutorial guides on Google's site for GWT here http://code.google.com/intl/sv/webtoolkit/doc/latest/tutorial/RPC.html

I have reach the end of 3. Serializing Java objects part of the tutorial and I couldn't get it to work. Basically I'm getting some error when calling the ASync service.

I have located the error to be here when. And yea the creation of that object fails thus the error is caught. I don't know if I have to continue on to the next step, but it says on the end of part 3 of the tutorial that I should get some numbers.

    AsyncCallback<StockPrice[]> callback = new AsyncCallback<StockPrice[]>() {
      public void onFailure(Throwable caught) {
        // TODO: Do something with errors.
      }

All the files needed to reproduce this is found on the homepage. Anyway anyone know what possible could be wrong here? This is the error output

[WARN] stockPriceServiceImpl: An IncompatibleRemoteServiceException was thrown while processing this call.
com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException: This application is out of date, please click the refresh button on your browser. ( Expecting version 5 from client, got 6. )
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamReader.prepareToRead(ServerSerializationStreamReader.java:432)
    at com.google.gwt.user.server.rpc.RPC.decodeRequest(RPC.java:236)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:186)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:224)
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler开发者_开发知识库.handle(SessionHandler.java:181)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:729)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:49)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:324)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:843)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)

It looks like you have an older version of gwt-servlet.jar or gwt-user.jar at your classpath..

For the same problem, check these link; http://groups.google.com/group/google-web-toolkit/browse_thread/thread/59a0309ffedf4e64/7667ea5361329d53?pli=1

http://squdgy.wordpress.com/2011/01/04/solving-expecting-version-5-from-client-got-6-problem-with-gwt/