Editing Print_Packing_Slip.tpl Not Showing

Hi guys, I'm trying to edit my packing slip document (print_packing_slip.tpl) in


but any changes made to it doesn't show up. I've tested adding some changes to invoice.tpl just to see if there's cache problem. But changes made to invoice.tpl does show up as expected.

Using CS 4.6.2; document editing mode not enabled.

Looking further by viewing page source and comparing it to the tpl file, it seems there 2 different version? (based on doctype header code)

view page source (?dispatch=orders.print_packing_slip&order_id=xxxxx)