Fixes pdf export when using range filters
Fixes pdf export when using range filters

http://code.google.com/p/zfdatagrid/issues/detail?id=522
omusico/zfdatagrid,ashishittechnosoft/zfdatagrid,ashishittechnosoft/zfdatagrid,ashishittechnosoft/zfdatagrid,ashishittechnosoft/zfdatagrid,omusico/zfdatagrid,omusico/zfdatagrid,omusico/zfdatagrid