I've made a grid with a single column containing a string, having based my code on http://www.sencha.com/examples/#Exam...needitablegrid. For some reason the model objects are never updated (i.e. a breakpoint in my setter never gets hit). What am I missing?

Code:
    private ValueProperties props = GWT.create(ValueProperties.class);


    public class Value {
        private String value;


        public String getValue() {
            return value;
        }


        public void setValue(String value) {
            this.value = value;
        }
    }


    interface ValueProperties extends PropertyAccess<Value> {


        @Editor.Path("value")
        ModelKeyProvider<Value> key();


        ValueProvider<Value, String> value();
    }



// widget setup
        final ListStore<Value> store = new ListStore<Value>(props.key());
        for (final String val : existingValues) {
            final Value value = new Value();
            value.setValue(val);
            store.add(value);
        }


        final List<ColumnConfig<Value, ?>> cols = new LinkedList<ColumnConfig<Value, ?>>();
        final ColumnConfig<Value, String> config = new ColumnConfig<Value, String>(props.value());
        cols.add(config);


        final ColumnModel<Value> model = new ColumnModel<Value>(cols);


        final Grid grid = new Grid(store, model);
        grid.setHideHeaders(true);
        grid.setBorders(true);


        editor = new GridInlineEditing(grid);
        editor.addEditor(config, new TextField());
        editor.setClicksToEdit(ClicksToEdit.ONE);


        if (store.size() == 0) {
            store.add(new Value());
        }


        editor.startEditing(new Grid.GridCell(0, 0));


        editor.addCompleteEditHandler(new CompleteEditEvent.CompleteEditHandler() {
            @Override
            public void onCompleteEdit(CompleteEditEvent event) {
                if (!Application.empty(store.get(store.size() - 1).getValue())) {
                    store.add(new Value());
                }
            }
        });