Unable to print/deliver purchase order

Hi All, Issue : Unable to deliver purchase order through Fax. In Detail : We have blanket Purchase Agreements prepared by Buyer X. Now Buyer X left the organisation. Subsequently we have end dated the buyer X. Now whenever we release against BPA, We are supposed to deliver the PO releases to vendor through FAX. We are able to deliver all POs and releases except POs prepared by buyer X. PO/releases delivered through automatic schedule program. Whenever schedule program runs the particular POs stucking the queue but not delivering to vendor. We are resolving temporatily this issue by extending the buyer enddate. Kindly help me how to resolve this issue. As the matter is high impact one. I request to respond as quickly as possible. Thank you JPR