Primary key of include structure affecting insert or modify records

Hi,

I am updating a standard table and the table has include structure. All the fields of the structure are keys of the table as well as there are 2 more fields which are original keys of the table. While I am trying to insert a new record in the table, keeping original key fields of the table same but giving new values to the other keys(include structure fields), record gets modified. It does not inert a new record.

Please note, include structure is placed at top of table and after that all the original fields of the table placed.(I am not aware how much this affects)

Please help.