Hey Doc!
I ran into the same problem when I tried to register on that site. I figured it was some kind of bot detection safeguard...
Anyway, I had the hardest time getting past that section. Unfortunately I don't remember what the exact problem was but when I realised what I was doing wrong it was kind ofa "duh" moment.
Keep trying!
Great site BTW! Not the place GBO is but a great site for it's perpose!