Using JAX-WS LogicalHandler - NullpointerException

Hi,

I'm using a very simple JAX-WS LogicalHandler in BEA WLS 10.0.
The handler works correctly if send sequential requests to my web service (with
handler). 
However, if i send parallel requests (used JMeter) to the web service I get the
following exception for each 10th - 20th request:

java.lang.NullPointerException
 at com.sun.xml.ws.handler.HandlerPipe.isHandleFalse(HandlerPipe.java:181)
 at com.sun.xml.ws.handler.HandlerPipe.process(HandlerPipe.java:109)
 at com.sun.xml.ws.handler.HandlerPipe.process(HandlerPipe.java:107)
 at weblogic.wsee.jaxws.MonitoringPipe.process(MonitoringPipe.java:98)
 at com.sun.xml.ws.protocol.soap.ServerMUPipe.process(ServerMUPipe.java:62)
 at com.sun.xml.ws.server.WSEndpointImpl$1.process(WSEndpointImpl.java:139)
 at
com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:15
3)
 at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:235)
 at
com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:
97)
 at weblogic.wsee.jaxws.HttpServletAdapter.post(HttpServletAdapter.java:36)
 at weblogic.wsee.jaxws.JAXWSServlet.doPost(JAXWSServlet.java:218)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
 at
weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecuri
tyHelper.java:226)
 at
weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.ja
va:124)
 at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283)
 at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
 at
weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAp
pServletContext.java:3370)
 at
weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.ja
va:321)
 at weblogic.security.service.SecurityManager.runAs(Unknown Source)
 at
weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletConte
xt.java:2117)
 at
weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java
:2023)
 at
weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1359)
 at weblogic.work.ExecuteThread.execute(ExecuteThread.java:200)
 at weblogic.work.ExecuteThread.run(ExecuteThread.java:172)


I've tried my example also both in Sun's Glassfish v1 and Glassfish v2. Here
everything works like a charm.
Therefore, I assume that it's a bug in BEA WLS 10.0. Could someone confirm my
assumption?