Thanks for the advice, a bit too late for me though. What annoys me is that most of the flight that allowed me to collect Skymiles were DL and AF, but the miles were at the time credited on the DL account while I would have preferred to credit them on my FlyingBlue account. In the end, I am stuck with a bit less than 23000 Skymiles that would be doing awesome in my FlyingBlue account.