Not sure if it may be the same issue as a few years ago but wouldn't surppise me. Carnival issued rules to TA's serval years ago to stop them from advertising prices less then the lowest fare Carnival was charging. At that time it was Liberty travel who was the big abusser. They had negoitaged with Carnival for each person booked thru them to get I belive it was $50 OBC. Then they would kickback a poration of their commision. Would run ads such as 5 day cruise $zzz/person thru Carnival------Book with Liberty for $yyy/person.
2004 Carnival Imagination Grand Cayman/O.R. Jamica
2006 Carnival Valor Eastern Caribbein
2008 Carnival Liberty Exotic W. Caribbein
2010 Carnival Spirit Mexican Rivera
2012 Carnival Freedom Exotic W. Caribbein