every single time e-tickets caused and still cause me (or/and the check-in staff in Zurich and all over the world) more problems than paper-tickets. As long as my two main-carriers, being in the same (Star-) alliance (UA and LH), still work on two non-comparable computer-systems, e-tickets of one or the other (or both carriers) add to my problem not to get checked-through to my final destinations. And it is even worse, if my itinerary starts/ends with a non Star-Alliance member (like sometimes Swissair for me).