Problem setting initial value of ComboBox with BeanItem

Hi,

I have a problem setting the initial value of a Combobox:

        ComboBox cb = new ComboBox("Please select a city");
        for (int i = 0; i < cities.length; i++) {
            cb.addItem(cities[ i ]
);
        }

        city = new City();
        
        BeanItem bi = new BeanItem<City>(city); 

        cb.setPropertyDataSource(bi.getItemProperty("name"));
        cb.setNullSelectionAllowed(true);
        cb.setImmediate(true);

        // Initialize combobox contents
        city.setName(cities[2]
); 

Thought city.setName() correctly sets the initial value of the Combobox, if I later select the blank option, city.getName() doesn’t returns null, but the initial value!

I’m using Vaadin version 6.8.8. Any help is appreciated.