After some research:
It would seem that the French "X-Files" were done by incompetent people, whose studies were at best incomplete and not scientific, and all dispositions were taken to prevent the document's studies by their peers for several YEARS. These people were furthermore engaging the whole CNES reputation by saying that there was undeniable proof some aliens had visited earth.
Now maybe it's the result of not taking seriously the UFO reports (maybe they deserved some real attention, not just denigration?) that these kind of people were put in charge of the whole departement.
Links: (use your favourite translator, Google translation looks good enough)
http://www.unice.fr/zetetique/articl...e_au_CNES.html
http://www.unice.fr/zetetique/articl...AN_GEIPAN.html
http://www.observatoire-zetetique.or...n=1&ecritId=37