Custom PO output type is not working in ME9F

Hi ,

When i try to output the PO using ME9F ,it does not output the message successfully.

This PO is configured for custom output type ZDC . Transmission medium as 8(Special function) and the dispatch time is " Send with periodically scheduled job".

First time the output fails when i click on output message button in ME9F screen ,but the order reference is created and sent to vendor. This can be seen in ME23N (Communication tab) for PO. But the processing status is Yellow and even NAST-VSTATProcessing status)  is 0 .

When i use the reprocess the same PO in ME9F and click on output message second time ,it seems to work. Also it becomes green this time and NAST table is updated with status as 1.

RV_message_update is used to update the NAST table.

Even i tried to execute the standard program RSNAST00 directly in se38 to output the PO. It behaves the same way.

Also while debugging ,the NAST_VSTAT becomes 1 at the time of NAST_UPDATE form in RSNAST00 . somehow the NAST-VSTAT becomes 0 again in the RV_MESSAGE_UPDATE function module?

Please guide how to proceed further.

Thanks.