Purchasing - View Document Problems

 We are using XML to produce the PO documents in PDF and have created templates to change the output depending on the status of the PO. Draft PO's (not yet approved) have the word "DRAFT" in large red letters splashed across the middle of the PO document which is not displayed when the status changes to approved. In some Po's however even though the status is changed the word DRAFT still appears. We have modified the template and uploeded again but when viewed from purchasing the original output is still displayed. Does the system cache the output and if so