I just made 1K for the first time, and did my first trip as such last week. I got upgraded on the non hub legs, but not the hub to hub. I went SFO to Denver (not upgraded), Denver to Atlanta (upgraded). Atlanta to IAD (upgrade) IAD to SFO (not upgraded).

The one I don't understand is IAD-SFO. Last week, I applied an RPU. It never cleared. I was on the phone with an agent when I did it (I didn't want to apply it to the ATL-IAD leg), and she said there were about 12 people on the upgrade list. When I checked in, I was close to the top of the list, but there were about 20 people (777) already cleared. I assume those were complimentary upgrades, but shouldn't the RPU have cleared first?

Again, I'm a 1K but was on a fairly cheap ticket.

Oh, and on international flights, I believe that you can only use the GPUs on higher fare buckets. The deeply discounted fares aren't eligible.