Flight to Antigua, which cabin.

I've booked a reward flight in g to Antigua, there appears to be lots of availability on this route in Upper. When checking the v-flyer database however it says 56% of the time the aircraft operating this route is a two cabin plane which does not have Upper. How are there Upper seats available nearly every day but the majority of the time on a plane without an Upper cabin?

It used to be operated with 2 class flights, but they are all 3 class now and have been for some time.

The A330-300's are all in three class layout now. I think some still need updating on the database here to reflect this.

Thanks, beginning to get a bit worried