JSF selectOneMenu ajax doesn't fire listener

The context is a form to add or modify an entry to/of a database table. Inside of it, I want to create a search/selection subform with :

1. A search text input that request the database to fill a selectOneMenu


2. The dynamically filled selectOneMenu to select a value


3. A classic selectOneMenu with values hard-coded

So far I achieved to get the search text input to work only if I am modifying an existing entry (which id is passed via URL). It doesn't work if when I'm creating a new one.

The second problem is (in the case of modifying an entry, which is working already), when a value is chosen in the selectOneMenu, the listener seems to not be called. But with the selectOneMenu that have hard-coded values, it works fine.

Here is the subform code :

<h:form>
    <h2>#{msg['addPeopleToFilm']}</h2>
    <div class="inputWrapper">  
        <h:inputText id="search" value="#{beanPersonne.recherche}" 
            valueChangeListener="#{beanPersonne.searchStringChanged}" >
            <f:ajax execute="search" render="output" event="valueChange" />
        </h:inputText>
        <label>#{msg['personSearch']}</label>
    </div>

    <div class="selectWrapper" >
        <h:selectOneMenu value="#{beanFilm.idToAdd}" id="output" valueChangeListener="#{beanFilm.idToAddChanged}">
            <f:selectItem itemLabel="#{msg['researchResults']} ›" itemSelected="true" itemDisabled="true" /> 
            <f:selectItems 
            value = "#{beanPersonne.resultatsRechercheDynamique}" 
            var="personne" 
            itemValue="#{personne.idPersonne}"
            itemLabel="#{personne.prenom} #{personne.nom}" /> 
            <f:ajax execute="output" render="idToAdd" event="valueChange" />
        </h:selectOneMenu>
    </div>

    <div class="selectWrapper" >
        <h:selectOneMenu value="#{beanFilm.categoryChoice}" id="category" valueChangeListener="#{beanFilm.categoryChoiceChanged}">
            <f:selectItem itemLabel="#{msg['type']} ›" itemSelected="true" itemDisabled="#{not empty beanFilm.categoryChoice}" /> 
            <f:selectItem itemLabel="#{msg['actor']} ›" itemValue="0" />
            <f:selectItem itemLabel="#{msg['producer']} ›" itemValue="1" />
            <f:selectItem itemLabel="#{msg['director']} ›" itemValue="2" />
            <f:ajax execute="category" render="categoryChoice" event="valueChange" />
            <f:ajax execute="category" render="category" event="valueChange" />
        </h:selectOneMenu>
    </div>

    <h:commandButton value="Test">
    </h:commandButton>

    <h2><h:outputText id="idToAdd" value="#{beanFilm.idToAdd}" /></h2>
    <h2><h:outputText id="categoryChoice" value="#{beanFilm.categoryChoice}" /></h2>
</h:form>

And here is my bean:

public class BeanFilm implements Serializable {

    private static final long serialVersionUID = 807253156212218187L;
    private Film film = new Film();
    private String recherche = new String();
    private String idToAdd = new String();
    private String categoryChoice = new String();
    private List<Film> resultatsRechercheDynamique = new ArrayList<Film>();

    public Film getFilm() {
        return film;
    }

    public void setFilm(Film film) {
        this.film = film;
    }

    public int getIdFilm() {
        return film.getIdFilm();
    }

    public void setIdFilm(int id) {
        film = DAOFilmJPA.getInstance().get(id);
    }

    public String getRecherche() {
        return recherche;
    }

    public void setRecherche(String recherche) {
        this.recherche = recherche;
    }

    public String getCheminAffiche() {
        File file = new File(FacesContext.getCurrentInstance().getExternalContext().getRealPath("/affiches/" + film.getIdFilm() + ".png"));
        if(file.exists())
            return "affiches/" + film.getIdFilm() + ".png";

        return "images/noimage.png";
    }

    public String enregistrer() {
        DAOFilmJPA.getInstance().save(film);
        return "filmSaveComplete";
    }

    public String doRecherche() {
        return "toResultatsRecherche";
    }

    public List<Film> getResultatsRechercheNotPro() {
        return DAOFilmJPA.getInstance().getFilmsParTitre(recherche);
    }

    public List<Film> getResultatsRechercheFilmPro() {
        return DAOFilmJPA.getInstance().getFilmsParTitre(recherche);
    }

    public List<Personne> getResultatsRecherchePersonnePro() {
        return DAOPersonneJPA.getInstance().getPersonnesParNom(recherche);
    }

    public String searchByTitle(String title)
    {
        recherche = title;
        this.resultatsRechercheDynamique = getResultatsRechercheFilmPro();
        return null;
    }

    public void searchStringChanged(ValueChangeEvent vce)
    {
        searchByTitle((String) vce.getNewValue());
    }

    public void idToAddChanged(ValueChangeEvent vce)
    {
        idToAdd = ((String) vce.getNewValue());
    }

    public void categoryChoiceChanged(ValueChangeEvent vce)
    {
        categoryChoice = ((String) vce.getNewValue());
    }

    public List<Film> getResultatsRechercheDynamique() {
        return resultatsRechercheDynamique;
    }

    public void setResultatsRechercheDynamique(
            List<Film> resultatsRechercheDynamique) {
        this.resultatsRechercheDynamique = resultatsRechercheDynamique;
    }

    public String getIdToAdd() {
        return idToAdd;
    }

    public void setIdToAdd(String idToAdd) {
        this.idToAdd = idToAdd;
    }

    public String getCategoryChoice() {
        return categoryChoice;
    }

    public void setCategoryChoice(String categoryChoice) {
        this.categoryChoice = categoryChoice;
    }
}