PLEASE CARNIVAL DON'T BAN ME FOR ASKING!!!
Cas, Don't worry about Carnival banning you for asking questions, or comments about something. When you mentioned this to me privately I thought you were kidding. No worries!
The reason I asked about the PVP vs. General Reservations, is for the exact reason that LHP gave you.
As Neil noted, I wouldn't cancel the reservation and re-book. I would transfer it if necessary. I have changed my reservation twice, and kept my same booking number and booking date to avoid the higher fuel supplement.
I would call them and ask for a PVP to contact you. Good Luck!