erreur Xfire Invocation org.codehaus.xfire.fault.XFireFault: Fault

Bonjour à tous !

Je suis vraiment bloqué sur ce problème, et merci à celui qui veut me donner un coup de vis.
J'ai l'exception suivant quand je tente d'invoquer mon web service XFire
callWebService() : org.codehaus.xfire.XFireRuntimeException: Could not invoke service.. Nested exception is org.codehaus.xfire.fault.XFireFault: Fault
org.codehaus.xfire.XFireRuntimeException: Could not invoke service.. Nested exception is org.codehaus.xfire.fault.XFireFault: Fault
org.codehaus.xfire.fault.XFireFault: Fault
at org.codehaus.xfire.fault.Soap11FaultSerializer.readMessage(Soap11FaultSerializer.java:31)
at org.codehaus.xfire.fault.SoapFaultSerializer.readMessage(SoapFaultSerializer.java:28)
at org.codehaus.xfire.soap.handler.ReadHeadersHandler.checkForFault(ReadHeadersHandler.java:108)
at org.codehaus.xfire.soap.handler.ReadHeadersHandler.invoke(ReadHeadersHandler.java:67)
at org.codehaus.xfire.handler.HandlerPipeline.invoke(HandlerPipeline.java:98)
at org.codehaus.xfire.client.Client.onReceive(Client.java:352)
at org.codehaus.xfire.transport.http.HttpChannel.sendViaClient(HttpChannel.java:179)
at org.codehaus.xfire.transport.http.HttpChannel.send(HttpChannel.java:82)
at org.codehaus.xfire.handler.OutMessageSender.invoke(OutMessageSender.java:26)
at org.codehaus.xfire.handler.HandlerPipeline.invoke(HandlerPipeline.java:98)
at org.codehaus.xfire.client.Client.invoke(Client.java:263)
at org.codehaus.xfire.client.XFireProxy.handleRequest(XFireProxy.java:77)
at org.codehaus.xfire.client.XFireProxy.invoke(XFireProxy.java:57)
at $Proxy0.findBook(Unknown Source)
at bnpparibas.acac.wservice.book.AincConnectWS.callWebService(AincConnectWS.java:141)
at bnpparibas.acac.wservice.book.AincConnectWS.<init>(AincConnectWS.java:63)
at bnpparibas.acac.wservice.book.AincWServiceClient.doPost(AincWServiceClient.java:80)
at bnpparibas.acac.wservice.book.AincWServiceClient.doGet(AincWServiceClient.java:64)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Unknown Source)

Voici le code d'invocation :
public void callWebService(String qsj, int in) throws MalformedURLException, Exception {

Service serviceModel = new ObjectServiceFactory().create(AincBookService.class);

XFire xfire = XFireFactory.newInstance().getXFire();
XFireProxyFactory factory = new XFireProxyFactory(xfire);

try {
m_client = (AincBookService)factory.create(serviceModel, m_url);

} catch (MalformedURLException e) {
System.out.println("WsClient.callWebService(): EXCEPTION1: " + e.toString());
e.printStackTrace();
}

//Invoke the service

try {
// m_client.findBook(qsj,typ);
System.out.println(" start compute...");
m_client.findBook(qsj,in);
m_serviceResponse = m_client.getBooksMap();
System.out.println(" End. Books list size =" +m_serviceResponse.size());

} catch (Exception e){
//serviceResponses = client.getBooksMap();
System.out.println(" Exception out type " + m_client.toString());
System.out.println(" EXCEPTION2 callWebService() : " + e.toString());
e.printStackTrace();
// serviceResponse = e.toString();
}

}