Case F-21/06: Judgment of the Civil Service Tribunal (Second Chamber) of 28 June 2007 — da Silva v Commission (Officials — Appointment in grade — Post of director advertised before 1 May 2004 — Amendment of the Staff Regulations — Article 2 and Article 5(5) of Annex XIII to the Staff Regulations — Classification by grade pursuant to new less-favourable provisions — Principle that all officials are entitled to reasonable career prospects)