dwr ajax IOException in Jetty

I get the error when I try to reverse ajax a piece of information from the java bean to the ajax script . can u please help me?

2007-07-22 19:20:57,064 [btpool0-2] WARN UrlProcessor-

Error: java.io.IOException: Error flushing buffered stream

2007-07-22 19:20:57,064 [btpool0-2] WARN UrlProcessor-

Sent 501

java.io.IOException: Error flushing buffered stream

at org.directwebremoting.dwrp.PollHandler.sendScript(PollHandler.java:37

at org.directwebremoting.dwrp.PollHandler$PollScriptConduit.addScript(Po

llHandler.java:483)

at org.directwebremoting.extend.EnginePrivate.remoteHandleException(Engi

nePrivate.java:118)

at org.directwebremoting.dwrp.PollHandler.handle(PollHandler.java:231)

at org.directwebremoting.servlet.UrlProcessor.handle(UrlProcessor.java:1

01)

at org.directwebremoting.servlet.DwrServlet.doPost(DwrServlet.java:120)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:767)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:860)

at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:423

)

at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:3

55)

at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:2

26)

at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:5

67)

at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHand

lerCollection.java:147)

at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.

java:126)

at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:1

19)

at org.mortbay.jetty.Server.handle(Server.java:248)

at org.mortbay.jetty.HttpConnection.handlerRequest(HttpConnection.java:3

60)

at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:282)

at org.mortbay.jetty.nio.SelectChannelConnector$HttpChannelEndPoint.run(

SelectChannelConnector.java:805)

at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool

.java:475)

2007-07-22 19:21:01,908 [btpool0-3] WARN UrlProcessor-