Setters get not fired on a dataTable (using paging)

Question

Problem: I use a dataTable in request scope and almost everyhting is working fine (I use an inputHidden to persist table property 'first'). I can page forward and backword.
The strange thing is, that if I navigate from page 1 to page 2 everything is working fine. All getters of the associated bean get called. But if I navigate from page 2 to 3 and so forth - no getters get called. But the actionListener is successfully called. The same problem If I navigate from page 2 to page 1. No getters are called, but the corresponding action is called.
Any known bugs? Ideas? Workarounds (without using session scope)?
Thanks.
Walter

Answer 1

I have simplified my table test project to allow further inspection.
Here is my code:
JSF-Page:
<f:view>
     <h:form>
          <h:inputHidden value="#{tt.first}"></h:inputHidden>
          <h:dataTable var="row" value="#{tt.model}" rows="5"
               first="#{tt.first}">
               <h:column>
                    <h:selectBooleanCheckbox value="#{row.selected}"></h:selectBooleanCheckbox>
               </h:column>
               <h:column>
                    <h:outputText value="#{row.name}"></h:outputText>
               </h:column>
               <f:facet name="footer">
                    <h:panelGroup>
                         <h:commandLink value="Previous"
                              actionListener="#{tt.onPreviousPage}"></h:commandLink>
                         <f:verbatim> </f:verbatim>
                         <h:commandLink value="Next" actionListener="#{tt.onNextPage}"></h:commandLink>
                    </h:panelGroup>
               </f:facet>
          </h:dataTable>
          <h:commandButton value="Submit"
               actionListener="#{tt.btnSubmit_OnClick}"></h:commandButton>
          <h:messages></h:messages>
     </h:form>
</f:view>
Backing-bean:
package tabletests;
import java.util.ArrayList;
import java.util.List;
import javax.faces.event.ActionEvent;
public class TableTestsBean {
     private List<TableTestsListItem> model;
     public TableTestsBean()
          model = new ArrayList<TableTestsListItem>();
          model.add(new TableTestsListItem("Worf"));
          model.add(new TableTestsListItem("Data"));
          model.add(new TableTestsListItem("Riker"));
          model.add(new TableTestsListItem("Picard"));
          model.add(new TableTestsListItem("Kirk"));
          model.add(new TableTestsListItem("Janeway"));
          model.add(new TableTestsListItem("Torres"));
          model.add(new TableTestsListItem("Neelix"));
          model.add(new TableTestsListItem("7of9"));
     public void setModel(List<TableTestsListItem> model)
          this.model = model;
     public List<TableTestsListItem> getModel()
          return model;
     private int first;
     public void setFirst(int first) { this.first = first; }
     public int getFirst() {     return first; }
     public void onNextPage(ActionEvent event){ first+=5; }
     public void onPreviousPage(ActionEvent event){ first-=5; }
     public void btnSubmit_OnClick(ActionEvent event)
          // Action listener gets successfully called, but
          // setters are not called!
"DataRow"-Bean:
package tabletests;
public class TableTestsListItem {
     private String name;
     private boolean selected;
     public String getName() {
          return name;
     public void setName(String name) {
          this.name = name;
     public TableTestsListItem() {}
     public TableTestsListItem(String name)
          this.name = name;
     public boolean getSelected() {
          return selected;
     public void setSelected(boolean selected) {
          this.selected = selected;
faces-config - Relevant part:
    <managed-bean>
          <managed-bean-name>tt</managed-bean-name>
          <managed-bean-class>tabletests.TableTestsBean</managed-bean-class>
          <managed-bean-scope>request</managed-bean-scope>
     </managed-bean>I would be very grateful if someone could test this code or give me a hint what is wrong.
Thanks.
Walter