French requirements for solo flight

I got up at 3:30 am so I could call and was told that the French
government has cracked down and that I need to send not a copy of my
pilots license but a "certified" copy which they indicated had to be
signed by a government official. I could not get a better description
of exactly what they wanted so does anyone know what they mean. I
wonder if a notarized copy would suffice?

Also, since I fly out of Houston which is flat as a pancake and
therefore hotter means better soaring, can anyone explain why they are
booked solid in April? What type of conditions should I expect the
first week of June?