Empty combo box when filling it with a RPC service

[PhiLho]

In a UiBinder file, I define a combo box in a HBoxLayoutContainer (along with some other components that are displayed fine):

<container:child layoutData="{boxLayoutData_MarginRight}">
  <form:FieldLabel text="Granularity">
    <form:widget>
      <form:ComboBox ui:field="granularityCombo"
          allowBlank="false" triggerAction="ALL"/>
    </form:widget>
  </form:FieldLabel>
</container:child>

In the Java code, I define it as:

GranularityProperties m_props = GWT.create( GranularityProperties.class );
ListStore<Granularity> m_store = new ListStore<Granularity>( m_props.key() );

@UiField(provided = true)
ComboBox<Granularity> granularityCombo;

and in the asWidget() method, I create it:

  granularityCombo = new ComboBox<Granularity>( m_store, m_props.name() );
  GranularityServiceAsync service = (GranularityServiceAsync) GWT.create( GranularityService.class );
  final AsyncCallback<List<Granularity>> callback = new AsyncCallback<List<Granularity>>()
  {
     @Override
     public void onSuccess( List<Granularity> result )
     {
        System.out.println("OK with " + result);
        m_store.addAll( result );
     }

     @Override
     public void onFailure( Throwable caught )
     {
        // Log error? Display message...
        System.out.println("Oops " + caught);
     }
  };
  service.getGranularities( callback );

My service works, I get data in the result parameter.

But the combo box is empty, displayed as a button with a >> content, showing a tiny empty list.
Does the combo box support filling the store asynchronously as above?
The GXT Demos/examples get their data from the client side, so it is hard to tell if I make a mistake or if that's a bug in the Beta 2.

[gishmo]

I have several combo boxes working with data from RCP calls.

But, I don't use UiBinder ...

[PhiLho]

The problem has disappeared with Beta3.
Thanks.