Ext.override(Ext.grid.CellModel, {
    initKeyNav: function(view) {
        var me = this;

        if (!view.rendered) {
            view.on('render', Ext.Function.bind(me.initKeyNav, me, [view], 0), me, {single: true});
            return;
        }

        view.el.set({
            tabIndex: -1
        });

        // view.el has tabIndex -1 to allow for
        // keyboard events to be passed to it.
        me.keyNav = new Ext.util.KeyNav({
            target: view.el,
            ignoreInputFields: true,
            up: me.onKeyUp,
            down: me.onKeyDown,
            right: me.onKeyRight,
            left: me.onKeyLeft,
            tab: me.onKeyTab,
            enter: me.onKeyTab,
            scope: me
        });
    }
});