Issues in Service PO conversion through BAPI

Hello Gurus,

We have been working on Open purchase order conversions and have issues in service order conversion.

We are using the FM BAPI_PO_CREATE1 for load.

We get the below error when we try to load records with Item Category (PSTYP) =9.

",No instance of object type PurchaseOrder has been created. External reference:,Purchase order still contains faulty items, In case of account assignment, please enter acc. assignment data for item"

But when the exact same data is used to create the PO manually, we were able to create the PO succesfully.

We found an OSS note relevant to this: 1373051. But that was not much of help.

Please help.

Appreciate any responses.

Regards,

Raksha