Not necessarily because I tired putting in all the rooms on the Riviera deck before (couple of months ago) and kept getting the invalid message untill just recently I tried it again and this time I found it.
When is your cruise and what ship are you going on?
Carnival Victory 2000
Carnival Legend 2002
Carnival Valor 2005
Sounds like a maybe! Try that particular room number again. At some point, you *might* get a message indicating that it's your room. That's what happened to me.
CarnivalSensation February 2015
Carnival Dream November 2015
Carnival Fascination April 2014
Carnival Elation March 2011
Carnival Imagination Sept 2007
Carnival Sensation Dec 2006
RCI Sovereign of the Seas Sept 2006
Carnival Miracle Sept 2005
Carnival Glory Sept 2004
Carnival Fantasy Jan 2004