The thermoluminescence (TL) dates for burnt flint from the Middle Palaeolithic site, Pech de l'Aze IV, are significantly lower than the archaeological evidence suggests. The results of preliminary experiments to determine the cause of the discrepancy are presented. These studies include investigation of the variation of TL response with dose-rate, anomalous fading, trap depth determination and a simulation experiment. In addition, TL characteristics for the inner and outer portions of the flints have been measured. -- AATA