I have something similar creating a problem for me and my Medallion Account. I typically use my First MI Last as the format for my FF accounts. Well, on the intl flight that I am on always list it as First Middle Last. I don't have the luxury of booking my own tickets and it hasn't been a problem up until today. For some reason the Skymiles account computer entry will not accept my ticket with FIRST MIDDLE LAST. Strange and I was hoping for an oversold coach upgrade