Thanks for your quick responses!
I think you're right MSP! It looks like C+ is sold out for the flight, so I didn't clear automatically after booking. I don't want to push this too hard, since I've heard that some folks get removed from the First upgrade list when they are "upgraded" to C+. If it's looking like I won't make D1 I'll ask the Sky Club folks to add me to the C+ list.
Wish me luck!