GWT com JPA implementado por EclipseLink

Blz, moçada !!!

Estou trabalhando em um projeto, para aprendizagem …
Criei um serviço para listar todos as tuplas do BD.
As classes POJO foram criadas por eng. reversa . . .
e todas as classes realizam a interface Serializable . . .

import java.io.Serializable;
import javax.persistence.*;
import java.util.Set;


/**
 * The persistent class for the cliente database table.
 * 
 */
@Entity
@Table(name="cliente")
public class Cliente implements Serializable {
	private static final long serialVersionUID = 1L;

	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	private int codigo;

	private String login;
...
...
...

A seguinte exceção está sendo lançada:

[EL Info]: 2012-04-14 00:46:29.794--ServerSession(24117390)--EclipseLink, version: Eclipse Persistence Services - 2.1.3.v20110304-r9073 [EL Info]: 2012-04-14 00:46:31.111--ServerSession(24117390)--file:/media/DADOS/Profissional/workspaceGWT/ProjectJPAGWTLink/war/WEB-INF/classes/_ProjectJPAGWTLink login successful Starting Jetty on port 8888 [WARN] Exception while dispatching incoming RPC call com.google.gwt.user.client.rpc.SerializationException: Type 'org.eclipse.persistence.indirection.IndirectSet' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = {IndirectSet: not instantiated} at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:619) at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$ValueWriter$8.write(ServerSerializationStreamWriter.java:153) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:539) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeClass(ServerSerializationStreamWriter.java:709) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:748) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:621) at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126) at com.google.gwt.user.client.rpc.core.java.util.Collection_CustomFieldSerializerBase.serialize(Collection_CustomFieldSerializerBase.java:44) at com.google.gwt.user.client.rpc.core.java.util.ArrayList_CustomFieldSerializer.serialize(ArrayList_CustomFieldSerializer.java:39) at com.google.gwt.user.client.rpc.core.java.util.ArrayList_CustomFieldSerializer.serializeInstance(ArrayList_CustomFieldSerializer.java:51) at com.google.gwt.user.client.rpc.core.java.util.ArrayList_CustomFieldSerializer.serializeInstance(ArrayList_CustomFieldSerializer.java:28) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:740) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:621) at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$ValueWriter$8.write(ServerSerializationStreamWriter.java:153) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:539) at com.google.gwt.user.server.rpc.RPC.encodeResponse(RPC.java:616) at com.google.gwt.user.server.rpc.RPC.encodeResponseForSuccess(RPC.java:474) at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:571) at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208) at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248) at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62) at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:729) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:49) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at org.mortbay.jetty.Server.handle(Server.java:324) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505) at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:843) at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647) at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380) at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395) at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488) [ERROR] 500 - POST /projectjpagwtlink/ServicoBD (127.0.0.1) 57 bytes Request headers Host: 127.0.0.1:8888 Connection: keep-alive Accept: */* User-Agent: Mozilla/5.0 (X11; Linux i686) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.151 Safari/535.19 Accept-Encoding: gzip,deflate,sdch Accept-Language: pt-BR,pt;q=0.8,en-US;q=0.6,en;q=0.4 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Content-Length: 126 Origin: http://127.0.0.1:8888 X-GWT-Module-Base: http://127.0.0.1:8888/projectjpagwtlink/ Content-Type: text/x-gwt-rpc; charset=UTF-8 X-GWT-Permutation: HostedMode Referer: http://127.0.0.1:8888/ProjectJPAGWTLink.html?gwt.codesvr=127.0.0.1:9997 Response headers Content-Type: text/plain com.google.gwt.user.client.rpc.StatusCodeException: 500 The call failed on the server; see server log for details at com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.onResponseReceived(RequestCallbackAdapter.java:209) at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:287) at com.google.gwt.http.client.RequestBuilder$1.onReadyStateChange(RequestBuilder.java:395) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:616) at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103) at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71) at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172) at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:337) at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:218) at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136) at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561) at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269) at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91) at com.google.gwt.core.client.impl.Impl.apply(Impl.java) at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:213) at sun.reflect.GeneratedMethodAccessor29.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:616) at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103) at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71) at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172) at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:292) at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:546) at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:363) at java.lang.Thread.run(Thread.java:636)

Alguém já passou por essa situação ???
:?:
Da um help aí !!!