I need to create grid with checkbox in first column with grouping and summary enabled.

I was trying to do so by combining Check Grouping example with Live Group Summary example form GXT Demo. At the beginning everything worked just fine, but when I added checkbox column all group and summary rows disappeared. Here is a peace of sample code:

Code:
CheckBoxSelectionModel<BeanModel> sm = new CheckBoxSelectionModel<BeanModel>();

List<ColumnConfig> columns = new ArrayList<ColumnConfig>();

// Checkbox column
ColumnConfig column = sm.getColumn();
columns.add(column);

SummaryColumnConfig<Integer> summaryColumn = new SummaryColumnConfig<Integer>("orderDate", "Date", 100);
summaryColumnInt.setSummaryType(SummaryType.COUNT);
summaryColumnInt.setRenderer(new DateRenderer("dd/MM/yyyy"));
columns.add(summaryColumnInt);
columns.add(new SummaryColumnConfig<Integer>("orderId", "Id", 75));
columns.add(new SummaryColumnConfig<Integer>("source", "Source", 200));
columns.add(new SummaryColumnConfig<Integer>("target", "Client", 200));

BeanModelReader beanReader = new BeanModelReader();
OrdersProxy proxy = new OrdersProxy();
ListLoader<ListLoadResult<BeanModel>> loader = new BaseListLoader<ListLoadResult<BeanModel>>(proxy, beanReader);
GroupingStore<BeanModel> store = new GroupingStore<BeanModel>(loader);

Grid<BeanModel> ordersGrid = new Grid<BeanModel>(store, new ColumnModel(columns));
GroupSummaryView view = new GroupSummaryView();
view.setShowGroupedColumn(false);
view.setForceFit(true);
ordersGrid.setView(view);
ordersGrid.setSelectionModel(sm);
ordersGrid.addPlugin(sm);
In my opinion problem arises from mixing ColumnConfig and SummaryColumnConfig columns in one column model. Is there any other way to achieve my goal or is it just impossible thing to do.

Thanks in advance for your help.

PS. Sorry for my poor English, still learning.