They are definitely related, called and messed around online to see what happened as reservation was updated (pulling two from either dropped the other one). No big deal, in the end I found 5x U on the 77W DFW-LHR on the day we wanted travel and saved the SWUs for the return, upgrading paid J to F I actually found a day when the flight we wanted had A7. I guess they dont expect to sell any F then ;-)