Erro ao usar java.util.ArrayList em property no formbean struts

Fala pessoal…
estou desenvolvendo meu projeto final, e estou encontrando um problema. No meu form eu tenho um property assim <form-property name="detalhe" type="java.util.ArrayList"/> . Ao iniciar a action, eu dou um ArrayList detalhe = new ArrayList(); detalhe.add(new Pedido()); dynaForm.set("detalhe",detalhe); que coloca um objeto pedido neste property do form.
Na minha jsp eu tenho <c:forEach items="${fazerPedidoForm.map.detalhe}" var="detalhe" varStatus="i"> <tr> <td class="campo"><b><c:out value="${i.count}"/></b></td> <td class="campo"> <html:text property="codigoItemAlimento" name="detalhe" indexed="true"/> </td> </tr> </c:forEach> Até aí tudo bem, mas ao dar um submit, qualquer que seja, retorna a seguinte mensage 1606672 ERROR [http-8080-Processor24] org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/E-ORDER].[action] - Servlet.service() for servlet action threw exception java.lang.IndexOutOfBoundsException: Index: 0, Size: 0 at java.util.ArrayList.RangeCheck(ArrayList.java:547) at java.util.ArrayList.get(ArrayList.java:322) at org.apache.struts.action.DynaActionForm.get(DynaActionForm.java:254) at org.apache.commons.beanutils.PropertyUtils.getIndexedProperty(PropertyUtils.java:456) at org.apache.commons.beanutils.PropertyUtils.getIndexedProperty(PropertyUtils.java:410) at org.apache.commons.beanutils.PropertyUtils.getNestedProperty(PropertyUtils.java:752) at org.apache.commons.beanutils.PropertyUtils.getProperty(PropertyUtils.java:783) at org.apache.commons.beanutils.BeanUtils.setProperty(BeanUtils.java:793) at org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:726) at org.apache.struts.util.RequestUtils.populate(RequestUtils.java:495) at org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:798) at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:205) at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164) at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415) at javax.servlet.http.HttpServlet.service(HttpServlet.java:709) 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:178) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) 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:148) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869) at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:667) at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527) at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684) at java.lang.Thread.run(Thread.java:595) . Gostaria de saber o pq.