I am interested in using some old World Perks miles to upgrade to first class on an upcoming trip in December. I called Northwest, and they said that the upgrade was available, but I needed to call Continental and get the itinerary split, as there are 2 others travelling and only I am upgrading. I called Continental and they split the itinerary. Then I called Northwest back, and they said that they couldn't upgrade me until 30 days before the flight. Is this correct? The first NW agent made it sound like she could upgrade me right now without any problems. Does Continental really have a 30 day rule?