It is so weird how some people have so much trouble with linking their reservation and then some of us just click and go. I just don't understand.
My guess is that any reservation that isn't a setup in a standard manner are the ones that they're having problems with. In our case because it was an aeroplan reservation and a 2nd guest had to be added it created the environment for the snowball to start rolling down the cliff. In Tess's case it was 3 reservations under the same name. Most of the problems I've read about are in cases where the original res didn't show the right number of people, or some other detail, not unusual in the hotel world . In the usual course (not dealing with MDE) there would be no issues with the reservation but because S/D and Disney have 2 separate res systems they just are not in sync nor do they understand ea others systems nor are they set up to deal with the (normally) insignificant detail.