Problema Com SelectOneMenu

<r:modalPanel id="organizaGrauParentesco" autosized="true" minWidth="500">
	   	<f:facet name="header">
			<h:outputText value="Tela de Atualização do Dependente!" />
		 </f:facet>
		 
		 <f:facet name="controls">
			 <h:panelGroup>
				<h:graphicImage value="/images/delete.gif" id="hidelink" styleClass="hidelink"/>
				<r:componentControl for="organizaGrauParentesco" attachTo="hidelink" operation="hide" event="onclick" />
			</h:panelGroup>
		</f:facet>
		
			<a4j:form>
			
				<r:dataTable var="item" value="#{mbOrcamento.listaDependentes}" >
	   		
			   		<r:column style="width: 320px;">
			   			<f:facet name="header" >
			   				<h:outputText value="Nome"/>
			   			</f:facet>
			   				<h:outputText value="#{item.nome}" />
			   		</r:column>
			   		
			   		<r:column style="width: 120px; text-align: center">
			   			<f:facet name="header" >
			   				<h:outputText value="Data Nascimento"/>
			   			</f:facet>
			   				<h:outputText value="#{item.dt_Nascimento}">
			   					<f:convertDateTime pattern="dd/MM/yyyy" timeZone="America/Sao_Paulo" locale="pt_BR"/>
			   				</h:outputText>
			   		</r:column>
			   		
			   		<r:column style="width: 130px; text-align: center">
			   			<f:facet name="header" >
			   				<h:outputText value="Grau Parentesco"/>
			   			</f:facet>
			   				<h:selectOneMenu value="#{item.nm_Dependencia}">
			   					<f:selectItems value="#{mbOrcamento.listaGrauParentesco}" /> 
			   				</h:selectOneMenu>
			   		</r:column>
			   		
			   		<f:facet name="footer">
							<r:datascroller />
						</f:facet>
			   	</r:dataTable>
				
				<br />
				<br />
				
				<a4j:commandButton id="btnAtualizar" image="/images/atualizar.jpg" action="#{mbOrcamento.ok}" />
			   	<a4j:commandButton id="btnCancelar" image="/images/cancelar.jpg" action="#{mbOrcamento.cancel}"/>
			   	<r:componentControl for="organizaGrauParentesco" attachTo="btnCancelar"
													                    operation="hide" event="onclick" />
				
			</a4j:form>
		 
   </r:modalPanel>	

<a4j:form>
	<a4j:commandButton value="xD" oncomplete="#{r:component('organizaGrauParentesco')}.show();" action="#{mbOrcamento.returnListaDependente}" reRender="organizaGrauParentesco"/>
</a4j:form>

public void ok(){
		System.out.println("ok");
	}
	
	public void cancel(){
		System.out.println("Cancelado");
	}
	
	public void returnListaDependente(){
		OrcamentoItemPF o =  new DAOFactory().getOrcamentoItemPFDAO().procurarPorId(1);
		listaDependentes = o.getListaDependentes();
		for(Dependente d : listaDependentes){
			System.out.println(d.getNome() + " | " + d.getNm_Dependencia());
		}
	}