As "Le Monde" is generally regarded as the most reliable french newspaper, I thought I'd quote it here :
Les boîtes noires de l'Airbus Rio-Paris repérées - Société - Le Monde.fr
Quick and dirty translation : the "Nautile" submarine has beed diving on June 22nd in an attempt to locate the black boxes of the Air France Airbus that vanished on June 1st over the southern Atlantic. It was guided by a very faint signal picked up by one the the French Navy ships. Search is made very difficult due to very montainous nature of the seabed with depths around 5,000 meters. The batteries of the black boxes should last for another week or so.