Judgment of the Court of First Instance of 17 September 2003 in Joined Cases T-309/01 and T-239/02: Peter Biegi Nahrungsmittel GmbH and Commonfood Handelsgesellschaft für Agrar-Produkte mbH v Commission of the European Communities (Subsequent accounting for import duties — Conditions — Article 220(2)(b) of Regulation (EC) No 2193/92 — Detectable error — Duty of care — Regulation (EC) No 774/94 — Combined nomenclature — WTO tariff quotas)