a4j:support in h:datatable

[Michał Jurczuk]

a4j:support in h:datatable doesn't call actionListener

                <h:dataTable id="table1" value="#{answer.matrix}" var="m">
                    <h:column>
                        <h:panelGrid columns="2" >
                            <h:outputText value="Columns:"/>
                            <h:selectOneListbox value="#{m.amount_column}" size="1">
                                <f:selectItems value="#{m.list_amount_column}"/>
                                <a4j:support event="onchange" actionListener="#{m.createMatrix}" reRender="matrix_draw"/>
                            </h:selectOneListbox>
                        </h:panelGrid>
                    </h:column>
                </h:dataTable>

 <managed-bean>
        <managed-bean-name>answer</managed-bean-name>
        <managed-bean-class>com.Answer</managed-bean-class>
        <managed-bean-scope>request</managed-bean-scope>
    </managed-bean>

m.amount_column doesn't change
and it doesn't call m.createMatrix

why?? please help