So frustrated with UA's online system for paid upgrades. It almost never works right. I have a DEN-LGA flight next week that I originally booked in E+. I noticed yesterday that an upgrade to "Premium Seating" (aka First) was available at a very reasonable price. Paid for the upgrade and then tried to select seats: they all show as occupied on the .bomb seating chart, so I can't get a seat assignment. Checked Expert Flyer and there are 9 seats open (A9/F9), including two aisle seats (which I'd prefer, of course) -- but I can't get assigned to one. I wish this was the first time this has happened, but no, it's more the rule than the exception. Last month I ended up paying for the same upgrade to E+ TWICE on one leg because of a similar glitch. I had paid for Premier Travel (which includes E+ on all available segments) when I booked, but the equipment changed on one leg and I was moved to a regular E seat. I tried to move myself back to an E+ seat online, but the system was requiring me to pay again. I then spent over an hour on the phone with the Indian call center, escalating the problem repeatedly to "higher ups," none of whom could fix this. They claimed it was impossible to assign an E+ seat because there were none available (untrue - both .bomb and Expert Flyer showed plenty of E+ seats open). It was a long leg and I really, really wanted to be in E+, so I finally gave up and paid $39 for the upgrade (again) in order be sure of an E+ seat. Same thing happened a few months back, but in that case I didn't care that much about E+ on the affected leg (it was the 17-minute flight from COS-DEN) so I just waited and the system allowed me to move back to E+ during online check-in 24 hours before the flight. I know I should have pursued the $39 overcharge with UA and tried to get a refund, but frankly I'd already sunk so much time into this mess already... Sorry for the rant. Am I the only one having this problem regularly? I don't recall seeing it mentioned, but perhaps I've missed the thread(s).