ws_delivery_update performs differently in background

Hello All (and help)

I am trying to PGI an outbound delivery using ws_delivery_update (also tried ws_delivery_update_2).

Using VL02N or using the SE37 test tool, the delivery can be PGI'd successfully.

However, when executed remotely from the sub-system, the RFC returns an error that "Customer xxxxx is not defined in company code 0321" which is true. The fulfilling plant is in company 0321, however the customer is in company 0330.

        With WS_DELIVERY_UPDATE

            .Exports("DELIVERY")                        = ZeroFill(msDelivery,10)

            .Exports("COMMIT")                          = "X"

            .Exports("IF_DATABASE_UPDATE")              = "1"

            .Exports("VBKOK_WA").Fields("VBELN_VL")     = ZeroFill(msDelivery,10)

            .Exports("VBKOK_WA").Fields("VBTYP_VL")     = "L"

            .Exports("VBKOK_WA").Fields("VBELN")        = ZeroFill(msDelivery,10)       

            .Exports("VBKOK_WA").Fields("WABUC")        = "X"         'Post GI needs to be "X"

            .Exports("VBKOK_WA").Fields("WADAT_IST")    = postDate

            .Exports("VBKOK_WA").Fields("WADAT")        = postDate

            .Exports("VBKOK_WA").Fields("BOLNR")        = msShipmentProNo

        End With

Any ideas why this works in foreground mode but not in background?

Thanks for any input.