Do you see your status correctly reflected on the AF/KL website when viewing your reservation? There should be a little indicator with your passenger details. In the past people have reported cases of the system incorrectly reading a lower status than they really have, and some sort of customer service intervention being required to remove/re-add the FF information.

FWIW when this happened to me, nobody could figure out how to fix it before my flight, but all the live humans at the airport understood the benefits I was entitled to and were happy to manually force them through. Of course that does not help much for advance seat selection.