when Container fires ItemSetChange event?

Hi,
I built a BeanItemContainer subclass to add autocomplete function to BeanItemContainer. After Changing Container Content the ItemSetChange event is not fired (have a look at method filterItems).

public class QFAutoCompleteContainer extends BeanItemContainer<QFListEntry> {
    private static final long serialVersionUID = -5729620881451564295L;
    private QFDatabaseAccessService service;
    private String[] itemPropertyID;
    private String _table;


public QFAutoCompleteContainer(String Table, QFDatabaseAccessService service, String[] itemPropertyID) throws IllegalArgumentException {
        super(QFListEntry.class);
        this._table = Table;
        this.service = service;
        this.itemPropertyID = itemPropertyID;
    }

    @Override
    protected void addFilter(Filter filter) throws UnsupportedFilterException {
        SuggestionFilter suggestionFilter = (SuggestionFilter) filter;
        filterItems(suggestionFilter.getFilterString());
    }

    private void filterItems(String filterString) {
[b]        removeAllItems();
        List<QFListEntry> items = service.filterTableInDatabase(filterString, _table, itemPropertyID);
        addAll(items);[/b]
    }

I registerd the ItemSetChangeListener like that:

window.cbProdukt.addItemSetChangeListener(new ItemSetChangeListener() {
            
            @Override
            public void containerItemSetChange(ItemSetChangeEvent event) {
                // do some stuff here
            }
        });

Do I something wrong? I have no idea for different implementation. Can anybody help?

Thanks
Bernhard