I have 2 dynv6 addresses from dynv6.com and am currently Explorer level in the certification process. I have two different hosts registered with dynv6.com and both work when entered directly in the browser. The enthusiast test will not allow entering in a vhost/sub-folder for the one that is on port 80, neither will it allow specifying a custom HTTP port on the one that is in the root directory of another server.
Server on port 80 resides in /GpsGateServer/<utbunscd.txt>
Server on port 8086 resides in /<utbunscd.txt>
I can access the blank utbunscd.txt file when entering the addresses in browser using the dynv6 addresses. There is no way (that I know of) to change the Gps Gate IIS server to not operate out of a vHost folder although it is the only thing on port 80.