error in binding ZK6

<?page title="manage" contentType="text/html;charset=UTF-8"?>

<zk>
	<window title="Gestione contratti" apply="org.zkoss.bind.BindComposer"
			viewModel="@id('vm') @init('test.ManageContractsViewModel')">
		<caption image="/img/Text-Edit-32x32.png" />
					<button label="new" image="/img/edit_addx16.png" onClick="" self="@{action(contractDetail)}" />
		
	</window>
</zk>

<?page title="Dettaglio contratto" contentType="text/html;charset=UTF-8"?>

<zk>
	<window apply="org.zkoss.bind.BindComposer" viewModel="@id('vm') @init('test.ContractDetailViewModel')"
			title="Dettaglio contratto" self="@{define(content)}" >
		<caption image="/img/Text-Edit-32x32.png" />
		
		 
	</window>
</zk>

<?xml version="1.0" encoding="UTF-8"?>
<flow xmlns="http://www.springframework.org/schema/webflow"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/webflow
		http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd">
		
	<view-state id="manage-contracts">
		<transition on="contractDetail" to="contract-detail">
			<set name="flowScope.contractDetail" value="self.attributes.selectedContract"></set>
		</transition>
	</view-state>
	
	<view-state id="contract-detail">
		<transition on="back" to="manage-contracts" />
	</view-state>
</flow>

15-nov-2012 10.49.22 org.zkoss.zk.ui.impl.UiEngineImpl handleError:1351
GRAVE: >>org.springframework.webflow.execution.FlowExecutionException: Exception thrown in state 'manage-contracts' of flow 'main/contract-administration'
>>java.lang.ClassCastException: org.zkoss.bind.AnnotateBinder cannot be cast to org.zkoss.zkplus.databind.DataBinder
>>	at org.zkoss.spring.webflow.execution.ZkFlowView.bind(ZkFlowView.java:140)
>>	at org.zkoss.spring.webflow.execution.ZkFlowView.processUserEvent(ZkFlowView.java:96)
>>	at org.springframework.webflow.engine.ViewState.handleEvent(ViewState.java:248)
>>	at org.springframework.webflow.engine.ViewState.resume(ViewState.java:218)
>>	at org.springframework.webflow.engine.Flow.resume(Flow.java:545)
>>	at org.springframework.webflow.engine.impl.FlowExecutionImpl.resume(FlowExecutionImpl.java:259)
>>	at org.springframework.webflow.executor.FlowExecutorImpl.resumeExecution(FlowExecutorImpl.java:169)
>>	at org.springframework.webflow.mvc.servlet.FlowHandlerAdapter.handle(FlowHandlerAdapter.java:183)
>>	at org.zkoss.spring.webflow.mvc.servlet.ZkFlowHandlerAdapter.handle(ZkFlowHandlerAdapter.java:81)
>>	at org.springframework.webflow.mvc.servlet.FlowController.handleRequest(FlowController.java:174)
>>	at org.zkoss.spring.webflow.mvc.servlet.ZkFlowControllerListener.afterProcessEvent(ZkFlowControllerListener.java:120)
>>	at org.zkoss.zk.ui.impl.EventInterceptors.afterProcessEvent(EventInterceptors.java:159)
>>	at org.zkoss.zk.ui.util.Configuration.afterProcessEvent(Configuration.java:2533)
>>	at org.zkoss.zk.ui.impl.DesktopImpl.afterProcessEvent(DesktopImpl.java:1216)
>>	at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:137)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1702)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1487)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1204)
>>	at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:558)
>>	at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:456)
>>	at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:464)
>>	at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
>>	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.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:366)
>>	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109)
>>	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:109)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:167)
>>	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
>>	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
>>	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
>>	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
>>	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
>>	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
>>	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
>>	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
>>	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
>>	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
>>	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
>>	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
>>	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
>>	at java.lang.Thread.run(Thread.java:679)