An Air France Airbus A320-200, registration F-GKXT performing flight AF-1695 from Budapest (Hungary) to Paris Charles de Gaulle (France), was preparing for departure at the gate, the crew requested de-icing at the stand. After de-icing was completed all four cabin crew members complained of head ache. After assessing the situation the captain decided to cancel the flight. The flight attendants were taken to the airport medical services. The passengers were rebooked onto other flights. The occurrence aircraft positioned to Paris about 3.5 hours later and resumed service. Hungary's TSB reported minor injuries to the flight attendants and opened an investigation into the occurrence.