Originally Posted by ADLFO

I can confirm as something similar happened to me in May. Original flights, all on NW metal. Originating NW flight goes mechanical, so I get rebooked on DL metal two days later. Saw the DL flights on my itineraries on DL.com so I thought all was well. Spent two hours the night before the DL replacement flights on the phone with both DL and NW who said the rebook was never ticketed. It took them forever, and I got bounced three times, but a Seattle NW agent on the phone with someone else finally got it ticketed. I'm just glad I tried to OLCI the night before, as it would not allow me to check in and this alerted me to there being a problem. So, make sure you are TICKETED, as your itin showing online means little or nothing.