I reserved a room at the Westin Casuarina on Grand Cayman for late-March using Starwood points. There are a number of rooms available at various levels, but they tell me that the hotel does not allow room upgrades using points. Is this normal?

They tell me that as a Gold member, I will be eligible for an upgrade upon checkin if available, but of course my feeling is that Carribean hotels generally have very high occupancy in March.

Any thoughts on above -- is it common for a hotel to refuse to accept Starwood points for upgrades?