Problemas com Axis

Pessoal, alguém tem alguma idéia do que pode ser isso?

Exception in thread "main" AxisFault
 faultCode: {http://schemas.xmlsoap.org/soap/envelope/}Server.userException
 faultSubcode: 
 faultString: java.lang.reflect.InvocationTargetException
 faultActor: 
 faultNode: 
 faultDetail: 
        {http://xml.apache.org/axis/}stackTrace: AxisFault
 faultCode: {http://schemas.xmlsoap.org/soap/envelope/}Server.userException
 faultSubcode: 
 faultString: java.lang.reflect.InvocationTargetException
 faultActor: 
 faultNode: 
 faultDetail: 
java.lang.reflect.InvocationTargetException
        at org.apache.axis.message.SOAPFaultBuilder.createFault(SOAPFaultBuilder.java:260)
        at org.apache.axis.message.SOAPFaultBuilder.endElement(SOAPFaultBuilder.java:169)
        at org.apache.axis.encoding.DeserializationContextImpl.endElement(DeserializationContextImpl.java:1015)
        at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1675)
        at org.apache.crimson.parser.Parser2.content(Parser2.java:1926)
        at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1654)
        at org.apache.crimson.parser.Parser2.content(Parser2.java:1926)
        at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1654)
        at org.apache.crimson.parser.Parser2.parseInternal(Parser2.java:634)
        at org.apache.crimson.parser.Parser2.parse(Parser2.java:333)
        at org.apache.crimson.parser.XMLReaderImpl.parse(XMLReaderImpl.java:448)
        at javax.xml.parsers.SAXParser.parse(SAXParser.java:345)
        at org.apache.axis.encoding.DeserializationContextImpl.parse(DeserializationContextImpl.java:242)
        at org.apache.axis.SOAPPart.getAsSOAPEnvelope(SOAPPart.java:538)
        at org.apache.axis.Message.getSOAPEnvelope(Message.java:376)
        at org.apache.axis.client.Call.invokeEngine(Call.java:2583)
        at org.apache.axis.client.Call.invoke(Call.java:2553)
        at org.apache.axis.client.Call.invoke(Call.java:2248)
        at org.apache.axis.client.Call.invoke(Call.java:2171)
        at org.apache.axis.client.Call.invoke(Call.java:1691)
        at ICLembreteClient.getCompromissosDia(ICLembreteClient.java:25)
        at ICLembreteClient.main(ICLembreteClient.java:44)
java.lang.reflect.InvocationTargetException
        at org.apache.axis.message.SOAPFaultBuilder.createFault(SOAPFaultBuilder.java:260)
        at org.apache.axis.message.SOAPFaultBuilder.endElement(SOAPFaultBuilder.java:169)
        at org.apache.axis.encoding.DeserializationContextImpl.endElement(DeserializationContextImpl.java:1015)
        at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1675)
        at org.apache.crimson.parser.Parser2.content(Parser2.java:1926)
        at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1654)
        at org.apache.crimson.parser.Parser2.content(Parser2.java:1926)
        at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1654)
        at org.apache.crimson.parser.Parser2.parseInternal(Parser2.java:634)
        at org.apache.crimson.parser.Parser2.parse(Parser2.java:333)
        at org.apache.crimson.parser.XMLReaderImpl.parse(XMLReaderImpl.java:448)
        at javax.xml.parsers.SAXParser.parse(SAXParser.java:345)
        at org.apache.axis.encoding.DeserializationContextImpl.parse(DeserializationContextImpl.java:242)
        at org.apache.axis.SOAPPart.getAsSOAPEnvelope(SOAPPart.java:538)
        at org.apache.axis.Message.getSOAPEnvelope(Message.java:376)
        at org.apache.axis.client.Call.invokeEngine(Call.java:2583)
        at org.apache.axis.client.Call.invoke(Call.java:2553)
        at org.apache.axis.client.Call.invoke(Call.java:2248)
        at org.apache.axis.client.Call.invoke(Call.java:2171)
        at org.apache.axis.client.Call.invoke(Call.java:1691)
        at ICLembreteClient.getCompromissosDia(ICLembreteClient.java:25)
        at ICLembreteClient.main(ICLembreteClient.java:44)

Meu Web Service:

import java.util.*;

import login.LoginFacade;
import tarefas.TarefasFacade;
import auxiliares.confXml.ConfAdmin;
import beans.Compromisso;
import beans.Pessoa;
import beans.Usuario;

import com.thoughtworks.xstream.XStream;
import compromissos.CompromissosFacade;

public class ICLembrete {
    
    public String getCompromissosDia(String uid, Calendar data) {
        
        XStream xstream = new XStream();
        xstream.alias("Pessoa", Pessoa.class);
        xstream.alias("Compromisso", Compromisso.class);
        xstream.alias("LinkedList", LinkedList.class);
        
        Pessoa pessoa = new Pessoa();
        pessoa.setUid(uid);
        
        LinkedList compromissos =    CompromissosFacade.getCompromissosDiaLembrete(pessoa, data);           
        
        return xstream.toXML(compromissos);
    }

Meu Cliente:

import java.util.*;
import java.rmi.RemoteException;
import javax.xml.namespace.QName;
import javax.xml.rpc.ServiceException;
import org.apache.axis.client.Call;
import org.apache.axis.client.Service;
import org.apache.axis.encoding.XMLType;

import com.thoughtworks.xstream.XStream;

public class ICLembreteClient {
    private String endpoint;
    private Service service;

    public ICLembreteClient(String endpoint) {
            this.endpoint = endpoint;
            service = new Service();                        
    }

    public String getCompromissosDia(String uid, Calendar hoje) throws ServiceException, RemoteException {
        Call call = (Call) service.createCall();
        call.setTargetEndpointAddress(endpoint);
        call.setOperationName("getCompromissosDia");        

        Object o = call.invoke(new Object[]{uid, hoje});
        return o.toString();
    }    
    
    public static void main(String[] args) throws Exception {
            ICLembreteClient ic = new ICLembreteClient(
                "http://localhost:8080/axis/ICLembrete.jws");

            System.out.println(ic.getCompromissosDia("vamorim", new GregorianCalendar()));
    }
}