I fly AMS to DEL and back often. It seems at least 2/3 of the time I have a seat assigned in advance and then at check in KLM randomly moves me. Today it was from my nice 15E to a middle seat in 42. Nice! When I call Delta or KLM they both tell me its the other airlines fault and there is nothing they can do. What am I doing wrong? I always make sure my Diamond number is on the reservation. Then after I book I always call / Tweet BOTH Delta and KLM to confirm. Today KLM tells me "It is not possible at present to reserve a seat on a flight operated by KLM and bearing a Delta Airlines flight number. We are working with Delta on a solution". ...?