check-in problem
Here's the one that annoys me most:
Sometimes, when I use online check-in, it gets me checked in fine but fails to load the images that need to be printed (the site dies / times out / etc during the process) and I have no boarding passes. It won't let me reload that page or go through the check-in process again, since I am "already checked in" and forces me to re-print my boarding passes at the airport (which, if you've ever tried to check-in at 5:30 am at SEA, you'll know how much time this wastes). It seems like you should be able to reprint your boarding passes online.