Store Reload does not clear selections of related grid

[Z]

Grid1 has Store1 and row selection model

load the grid, check a box

now call this

            App.Store1.load({
                scope: this,
                callback: function(records, operation, success) {
                }
            });

i would assume calling load would clear selections but it does not.
i need to call this manually.

            App.Grid1.getSelectionModel().clearSelections()

Thanks
/Z