A traveler's advisory: beware when making reservations with Air France via one of their SkyTeam Alliance partners. For the second time in this situation, I arrived at the airport with a confirmed reservation and seat assignments only to be told I actually had no seat. The gate agents explained that, while I received a confirmation from Continental (it's a code share), Air France's computer system is programmed to ignore seat assignment requests from its partner. Why? They couldn't say, but has apparently long been the case.
How to avoid having no seat? Once you get your confirmation numbers for an Air France-operated flight, log on to Air France's website, enter that number, and pick you seats again if you want to be sure to have them.
This turned out to be a only a minor inconvenience for me, but a family of four waiting behind me in line wasn't as lucky. They booked their flights via Travelocity which, acccording to the gate agents, the Air France system also ignores. This poor family never got to board the plane, even though they had their confirmed reservations in their hands.
Paris is wonderful, but in future I'm going to go out of my way to avoid arriving here by Air France.