Checkng in SFO -->IAD on 6/29, wife and I were told that you could not use the e-ticket machines if you were travelling on a reward ticket or a confirmed upgrade. As this applied to both of us, we accepted the explanation. Don't know if this is coincidental or not, but we also had to pass our luggage thru the stand-alone x-ray in the lobby, and got the familiar "SSSSS". Bit of a hassle on a busy morning.