I'm supposed to be on 930 tomorrow (may have to make a last minute change), and my Y to C upgrade still hasn't cleared. Y has gone from 0 to 4 to 2 to 4, C has been as low as 6, but today was back to C9. I don't know why that flight is so popular, but I bet my upgrade wouldn't clear until the gate, if at all, even though I'm 1K MM on an M fare.