It seems that every time my daughter flies on a UA partner airline I have a problem getting her MileagePlus number entered properly. With AirCanada, they rejected her MileagePlus number because her MP profile didn't have a middle name entered so they said "mismatch". I had to call MP to get the name middle name added. Now we're about to fly Copa, and they won't accept her MP number, saying "mismatch." I'm guessing that they don't like the fact that she has a middle name in her MP profile, so I'm going to have to call MP again, this time to remove her middle name. Or maybe not, the Copa reservation does have her middle name, so it seems like it should match right now. Anyone have any tips on how to deal with this sort of MP mismatch problem once and for all?