Thanks for your reply. The recordsource is a query. It's SQL is as follows:
SELECT tbl_lot.lot_id, tbl_lot_type.lot_type, tbl_lot.lot, tbl_lot.lot_comment, tbl_lot_status.lot_status, tbl_lot.number_wafers, tbl_user.my_username, tbl_lot.lot_started_timestamp
FROM tbl_user INNER JOIN...