When I'm using default BAPIs to update the SAP system (Production
Planning) it returns a Acknowledgement as Transaction complete. But in the
database the data is not updated.
I tried to check the program, and it's fine. Other examples works for the SD module.
This may be one of the BAPIs that require an extra commit. Try calling BAPI_TRANSACTION_COMMIT.
This was first published in February 2002