checkbox in grid template cause binding error

<grid id="scenarios" 
      model="@load(vm.scenarioModel) 
      @save(vm.scenarioModel,before='compareScenarios')">
	<auxhead>
		<auxheader colspan="4">
			<button label="Compare scenarios" disabled="@load(vm.cannotCompare)" onClick="@command('compareScenarios')"/>
			<space />
			<button	label="Change existing scenarios" />
			<space />
			<button label="Add new scenario" onClick="@command('addScenario')"/>
		</auxheader>
	</auxhead>
	<columns>
	    <column label="Compare" width="90px" align="center"/>
             <column label="Scenario name" />
	    <column label="Links" />
	    <column label="Evaluation state" />
	</columns>
	<template name="model" var="item">
		<row>
		    <checkbox check="@bind(item.selected)" onCheck="@command('selectionChange',state=self.checked, scenarioID=item.ID)"/>
		    <a label="@load(item.title)" />
		    <a label="@load(item.links)" />
		    <a label="@load(item.evaluationState)" />
		</row>
	</template>
</grid>

19-Sep-2012 06:02:33 org.zkoss.zk.ui.impl.UiEngineImpl handleError:1351
SEVERE: >>org.zkoss.zel.PropertyNotFoundException: Property 'check' not found on type org.zkoss.zul.Checkbox
>>	at org.zkoss.zel.BeanELResolver$BeanProperties.get(BeanELResolver.java:304)
>>	at org.zkoss.zel.BeanELResolver$BeanProperties.access$400(BeanELResolver.java:255)
>>	at org.zkoss.zel.BeanELResolver.property(BeanELResolver.java:429)
>>	at org.zkoss.zel.BeanELResolver.getType(BeanELResolver.java:115)
>>	at org.zkoss.zel.CompositeELResolver.getType(CompositeELResolver.java:131)
>>	at org.zkoss.zel.CompositeELResolver.getType(CompositeELResolver.java:131)
>>	at org.zkoss.xel.zel.XelELResolver.getType(XelELResolver.java:95)
>>	at org.zkoss.zel.impl.parser.AstValue.setValue(AstValue.java:210)
>>	at org.zkoss.zel.impl.ValueExpressionImpl.setValue(ValueExpressionImpl.java:256)
>>	at org.zkoss.xel.zel.ELXelExpression.setValue(ELXelExpression.java:50)
>>	at org.zkoss.bind.impl.BindEvaluatorXImpl.setValue(BindEvaluatorXImpl.java:50)
>>	at org.zkoss.bind.impl.LoadPropertyBindingImpl.load(LoadPropertyBindingImpl.java:81)
>>	at org.zkoss.bind.impl.PropertyBindingHandler.doLoadBinding(PropertyBindingHandler.java:171)
>>	at org.zkoss.bind.impl.PropertyBindingHandler.doLoad(PropertyBindingHandler.java:372)
>>	at org.zkoss.bind.impl.BinderImpl.loadComponentProperties(BinderImpl.java:1800)
>>	at org.zkoss.bind.impl.BinderImpl.loadComponent(BinderImpl.java:1777)
>>	at org.zkoss.bind.impl.BinderImpl.loadComponent(BinderImpl.java:1780)
>>	at org.zkoss.bind.tracker.impl.BindUiLifeCycle$1.onEvent(BindUiLifeCycle.java:69)
>>	at org.zkoss.zk.ui.AbstractComponent.onEvent(AbstractComponent.java:2736)
>>	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2685)
>>	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2648)
>>	at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:136)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1709)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1494)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage0(UiEngineImpl.java:463)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage(UiEngineImpl.java:316)
>>	at org.zkoss.zk.ui.http.DHtmlLayoutServlet.process(DHtmlLayoutServlet.java:215)
>>	at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:135)
>>	at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
>>	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
>>	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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:654)
>>	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:445)
>>	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:379)
>>	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:292)
>>	at org.zkoss.web.servlet.Servlets.forward(Servlets.java:837)
>>	at org.zkoss.zk.ui.http.ExecutionImpl.forward(ExecutionImpl.java:277)
>>	at org.zkoss.zk.ui.http.ExecutionImpl.forward(ExecutionImpl.java:286)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage0(UiEngineImpl.java:392)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage(UiEngineImpl.java:316)
>>	at org.zkoss.zk.ui.http.DHtmlLayoutServlet.process(DHtmlLayoutServlet.java:215)
>>	at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:135)
>>	at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
>>	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
>>	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:368)
>>	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$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:119)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
>>	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380)
>>	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:169)
>>	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:230)
>>	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
>>	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
>>	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
>>	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
>>	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
>>	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
>>	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
>>	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
>>	at java.lang.Thread.run(Thread.java:619)