HOLY COW!!! I fly 99% of the time out of SFO and they ALWAYS try and do that to me. After being stuck in the middle seat for about the 10th time, I pretty much gave up on upgrading (if it wasn't confirmed).
I'm just a 2P and only just now discovered this site so I didn't know they weren't supposed to do that!!
Maybe this is something they only do to 2Ps.