fixes issue #761
fixes issue #761
omusico/zfdatagrid,ashishittechnosoft/zfdatagrid,ashishittechnosoft/zfdatagrid,ashishittechnosoft/zfdatagrid,omusico/zfdatagrid,omusico/zfdatagrid,ashishittechnosoft/zfdatagrid,omusico/zfdatagrid