I had a lot of trouble on Wednesday night! DH and I were trying to sit down together with his new laptop from work. It would tell us we needed to enter the ages of our kids, but the box to do this never came up. I tried to associate it with our resort reservation thinking that might get them the info I needed, but nothing. We were pretty frustrated!
So I tried on another computer yesterday and I had no problem. I don't know if it was the timing, or the computer settings or what, but I am guessing it was just the computer settings. I would suggest to try on another computer and if that still doesn't work, let the Disney people know the problems you're having. They will probably be able to talk you through the issues.