I updated isls0002 to include new fields I created on the tdsls040 table. When I execute this include from a new session that updates the tdsls040 record, my history record is written corectly from the updated tdsls040 record. If I change a field using Maintain Header Lines, it re-writes the tdsls50 record from the previous tdsls050 record rather than writing it from an updated tdsls040.

Does anyone know if Maintain Sales Orders uses a different include to update history record (tdsls050)?

Is this problem still current?
Are you using Baan IV?

As I know, the include is used by tdsls4101. So I think, that is not the reason why you get those results.

Please remember that an include is included into the script at compilation-time.

To make changes of an include current, you have to recompile every script which uses this include.

But be carefull:

If you recompile a script from a different package-vrc than your life-environment, you can get trouble with pmc.
The recompiled object is allways stored at the life-environment on the hard-disk. Updates of the undlying vrc's are allways overruled by the recompiled object.

Not using iBaanERP, otherwise he would / should have changed the DAL to have things updated as he wants. In that case all writes would pass the new DAL and the problem would not be there (provided coded correctly).

Changing include files mean: also compile all objects that use the same include in a higher layer than the update standard. This may cause a problem with updates of the standard software that does not work, due to an object in a higher layer.