Advice please- booked a flight from US to Cancun in June for 2 people, M class fare. I'm EP, so we're in Main Cabin Extra, but there are 6 available seats in First, and would like to upgrade into 2 of them. I have two BXP1 upgrade certs, and want to use them. When I try to do so on line I get the message that this upgrade is "not eligible." Any ideas? Was going to call but figured I would ask the gurus here first. Thanks.