ME21N PO Update Terminated

Hi Experts,

We are unable to create PO documents. The error message is

as follows:

Update was terminated

System ID.... DGE

Client....... 010

User..... PATHAKA

Transaction.. ME21N

Update key... 4C34ACDF86BF014FE1008000AC120353

Generated.... 07.07.2010, 21:40:29

Completed.... 07.07.2010, 21:40:34

Error Info... ABAP/4 processor: COMMIT_IN_POSTING

The update termination happens when the message type parameter is set

to save immediately: Messages>select message>further data>dispatch

time='Send immediately (when saving the application).This happens with

all document types (NB, ZM). If you set the dispatch time to any other

option, you are able to save the purchase order.

Please Help .

Thanks in advance.