[RESOLVIDO] Converter JSF 2.0 + Primefaces

@FacesConverter(value="tipoUsuarioConverter", forClass=TipoUsuario.class)
public class TipoUsuarioConverter implements Converter {

	@Override
	public Object getAsObject(FacesContext context, UIComponent component, String value) throws ConverterException {
		if(value != null) {
			return new TipoUsuarioDAOImpl().buscarPorId(Integer.parseInt(value));
		}
		return null;
	}

	@Override
	public String getAsString(FacesContext context, UIComponent component, Object object) throws ConverterException {
		if(object != null && object instanceof TipoUsuario) {
			return ((TipoUsuario)object).getId().toString();
		}
		return null;
	}
}

<p:selectOneMenu id="selectTipo" value="#{usuarioBean.usuario.tipoUsuario}" effect="fade" converter="tipoUsuarioConverter">
	<f:selectItem itemLabel="Selecione o tipo de usuário" itemValue="" noSelectionOption="true"/>  
       	<f:selectItems value="#{usuarioBean.listaTipoUsuario}" var="t" itemLabel="#{t.tipo}" itemValue="#{t}"/>  
</p:selectOneMenu>

14/11/2011 10:26:51 com.sun.faces.lifecycle.ProcessValidationsPhase execute
AVISO: For input string: ""
java.lang.NumberFormatException: For input string: ""
	at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
	at java.lang.Integer.parseInt(Integer.java:470)
	at java.lang.Integer.parseInt(Integer.java:499)
	at br.com.sca.converter.TipoUsuarioConverter.getAsObject(TipoUsuarioConverter.java:18)
	at javax.faces.component.SelectUtils.doConversion(SelectUtils.java:191)
	at javax.faces.component.SelectUtils.matchValue(SelectUtils.java:99)
	at javax.faces.component.UISelectOne.validateValue(UISelectOne.java:153)
	at javax.faces.component.UIInput.validate(UIInput.java:967)
	at javax.faces.component.UIInput.executeValidate(UIInput.java:1233)
	at javax.faces.component.UIInput.processValidators(UIInput.java:698)
	at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
	at javax.faces.component.UIForm.processValidators(UIForm.java:253)
	at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
	at org.primefaces.component.panel.Panel.processValidators(Panel.java:284)
	at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
	at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
	at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
	at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1172)
	at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
	at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
	at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:964)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:304)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)