Confused re: Excursion Through Carnival

[peanutzmom]

OK, even though this deals with an excursion, I'm posting it here because my specific confusion is due to the Carnival website.

 

We want to go ziplining in St.Kitts. I have researched it online, and according to the website of the vendor, it is appropriate for ages 6 and up. As a Carnival Shore Excursion, it is listed as being available for ages 6 and up. So, I go to book the Excursion through Carnival this evening and get a message at the Check-Out Cart that one or more members of our party don't meet the age requirement. Our youngest is 11 years old, and all of her profile information reflects that. So, why can't I book this excursion?

 

Has anyone run into a similar problem before?

 

Has anyone done this excursion through Carnival before with kids 11 yrs old or under?

 

I have emailed Customer Care, and if I don't hear back this weekend I'll call them Monday during business hours. I was just curious to hear if anyone else has successfully booked this excursion through Carnival for someone 11 yrs old or younger.