Hi,
Could you please explain which movement type you are using for delivery? I mean is it 351 or 641.
Standard SAP wont allow you to create STO PO without maintaining purchasing view in the receiving plant. Please find below the documentation for the same for your reference.
http://help.sap.com/saphelp_erp60_sp/helpdata/en/43/81e107c4637104e10000000a1553f7/content.htm
Regards,
AKPT