I had an interesting experience with DNATA in Dubai. I got my ticket DXB-AMM from DNATA in 1992, all's well UNTIL I boarded the Royal Jordanian TriStar. The chief flight attendant looked at my ticket (yes, paper ticket yet), frowned, and informed me that my ticketed seat DID NOT EXIST on this aircraft! And they were fully booked!
Bottom line - because I was in the airline industry, and this was before the 9/11 WTC attack, the Captain invited me to ride the cockpit jump seat!