What dates are you going? The only thing that I could think of as a problem would be Pop Warner week, which is the 4th - 10th, if memory serves. Although these groups supposedly stay at the Value resorts, I've heard that overflow can be booked into the moderates, mainly CBR and POR.
Since you also need a room for 5 people (thus, AB side), maybe that's creating a problem, too.
I just checked 12/1-12/19 on the AP Best Rate site, and all rooms were showing availability at POR.
Did you talk to someone at CRO, or were you just using the WDW site?