When changing line-items there are a few conditions...
The following are mentioned in the function module documentation:
1. Minimum entry:
You must enter the order number in the SALESDOCUMENT structure.
You must always enter key fields for changes.
You must always specify the update indicator in the ORDER_HEADER_INX.
2. Commit control:
The BAPI does not run a database Commit, which means that the application must trigger the Commit so that the changes are read to the database. To do this, use the BAPI_TRANSACTION_COMMIT BAPI.
<b>But... What's not mentioned is that you also MUST pass the material number to the internal table for line-items (BAPISDITM).</b>
Hope it helps!
