Cascade dynamic rendering selectOneMenu doesn't work - jsf-2

Question

My problem I thougth is simple but I can't find a clear solution.
I have three selectOneMenu, and I want that the first one is always rendered, the second one is rendered if the first one has some value selected and the third one is rendered if the second has some value selected.
The relation between the first one and the second works well, but doesn't work between the second and the third.
When I change the value for the first selectOneMenu the second selectOneMenu is diplayed or hidden correctly.
But when I change the value for the second nothing happened to the third selectOneMenu, like if the f:ajax render isn't fired.
Bellow the jsf code:
<h:panelGrid columns="2">
<h:outputText value="Type Paiement" />
<h:selectOneMenu
value="#{employeurBean.idTypePaiement}">
<f:selectItem itemValue="" itemLabel="Choix typePaiement" />
<f:selectItems value="#{typePaiementBean.typesPaiement}" var="vtp"
itemLabel="#{vtp.libelle}" itemValue="#{vtp.idTypePaiement}" />
<f:ajax event="change" render="gmodp" />
</h:selectOneMenu>
</h:panelGrid>
<h:panelGrid id="gmodp">
<h:panelGroup rendered="#{employeurBean.idTypePaiement == 2}">
<h:outputText value="Mode Paiement" />
<h:selectOneMenu
value="#{employeurBean.idModePaiement}">
<f:selectItem itemValue="" itemLabel="Choix mode Paiement" />
<f:selectItems value="#{modePaiementBean.modesPaiement}" var="vmp"
itemLabel="#{vmp.libelle}" itemValue="#{vmp.idModePaiement}" />
<f:ajax event="change" render="grib"/>
</h:selectOneMenu>
</h:panelGroup>
</h:panelGrid>
<h:panelGrid id="grib">
<h:panelGroup rendered="#{employeurBean.idModePaiement == 1}">
<h:outputText value="Compte" />
<h:inputText value="#{employeurBean.compte}">
</h:inputText>
</h:panelGroup>
</h:panelGrid>
Is there any idea to achieve that.
Many thanks for your help

Answer 1

This construct will fail if the bean is request scoped and/or you're doing business actions (such as preloading the list) in getter methods instead of action listener methods. Ensure that the bean is been placed in the view scope and that you're doing business actions in action listener methods.
If that doesn't solve the problem, then you really have to post the backing bean code along the view code in your question.