Wondering your thoughts on a reported ES registration problem

I am wondering what your ideas might be on what could be causing users to have an experience like what was just sent to me below:

"Sean,

I attempted to register an account on DrCarney.com and ran into a funny error.

During the initial filling in of fields I omitted the year of my birth thinking it was not required. I got an error directing me to enter my birthday. All three birthday fields were clearned. I then enter all three birthday fields. The next screen tells me I need to confirm my email address (I'm guessing in the 2nd screen the confirm email field was blank and I failed to notice) but does not present me a field in which to confirm the email address.

I then closed the browser to start over, but when I reaccess http://drcarney.com/club and select Register, I get the same fully filled out registration screen where I need to confirm my email address but have no field with which to do so.

I'm guessing a cookie was installed on my browser and to start the registration over again I need to delete it.

I did confirm that drcarney.com did install a cookie a few minutes before I experienced the error, but the contents looks like gibberish and I'm not sure what the cookie details are.

Kevin"

I do use Recaptcha and wonder if it could have been involved.