Don't ask why - it is horrible enough but I am booked in Y (B fare) for a LHR - FRA flight. Wanted to waste some of my miles for an upgrade to CE. Called the EC and was informed that I cannot upgrade because it was not a BA issued ticket!!!! It was issued by AA. So much for alliances and small print. I now will accept my fate and/or rely on the kindness of strangers at the lounge/gate at LHR.

I just think this is one of the sillier rules associated with FFP's.