Note that while at SEA airport, I asked the ticket counter about this problem. They said that because I was ticketed within 96 hours of the flight (which was true), then the 'move to mint' automatic upgrade won't work. Apparently you have to be ticketed at least 96 hours before the flight in order for the auto upgrade to work. Of course, this subtle detail isn't anywhere in the Mosaic terms on jetblue.com that I could find. Neither the ticket counter or gate agent was able to 'force' a manual upgrade using the move to mint certificates. Pretty frustrating that after 3 separate calls to the Mosaic hot line prior to the flight, no one seems to know how the process actually works.