Sorry to be pedantic about this but I just want to be clear. Are you saying that my current seats (10 E&F) showing as confirmed in MMB, which I changed freely through status are not actually locked until I check-in (which will be 24 hours beforehand)? In other words, another passenger given a loose assignment can count the seconds until on-line check-in opens and have access to my seats because he is checking in ahead of me? My flight leaves at 23:00 and I don't know if I'll able to be on-line at exactly 23:00 the previous night.