Minor glitch in seat selection when booking upgrades:

After applying a GPU (and showing up correctly in "R") to an upcoming itinerary, the system gave me seats in C--but when I tried to pick seats, would only let me pick seats in F. I couldn't select from any of the other C seats despite a wide-open cabin.

The problem resolved itself after a half hour or so, but I was still scratching my head and wondering if I was going to end up with a double-upgrade (no, I didn't).