Originally Posted by PaulMSN
Don't choose "Seat Selection" from the Current Reservations screen. Instead click on "Change Current Northwest Reservations" on the left, then click View under "Reservation Details", then click on one of the seat numbers in the itinerary shown. This will bring up the seat map in the current window, cued to your first flight. There you can choose an exit row seat. Worked for me.
I actually stumbled upon this last night, thanks for the post though.
Very nice additions indeed. I was able to change my FC seat to 1A before check-in and it's still there (even though I haven't checked in yet for my flight this morning).
-RM