I have a reservation for May to which I applied an RPU to upgrade one way and miles the other. I cleared both ways at booking (R=5 showing in each direction). Unfortunately now United.com tells me that due to "modifications" made to my reservation I need to call to have the ticket reissued. I have been 1K for eighteen years and have never seen anything like this. Does anybody out there know if I really have to call to ensure I still actually have a ticket?