Axis2 - WstxIOException

hi guys... my english is not so good, but I'll try...
I get this exception in my webservice. If I call the service once and wait the response, it works fine, but if I call many times, this exception happens. has anybody gotten this exception? what is wrong? please, help - me. I lost one day trying looking for the solution, but i haven't found. tks

Lidio

2008-10-02 09:24:10,803 WARN org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/axis2].[AxisRESTServlet] - Servlet.service() for servlet AxisRESTServlet threw exception
org.apache.axis2.AxisFault: null; nested exception is:
com.ctc.wstx.exc.WstxIOException: null
at org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:221)
at org.apache.axis2.engine.AxisEngine.sendFault(AxisEngine.java:714)
at org.apache.axis2.transport.http.AxisServlet.handleFault(AxisServlet.java:319)
at org.apache.axis2.transport.http.AxisRESTServlet.doGet(AxisRESTServlet.java:52)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:17
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.jstripe.tomcat.probe.Tomcat55AgentValve.invoke(Tomcat55AgentValve.java:20)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:14
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:619)

anybody?