I have the same problem with windows 8. I havent found a work around yet. I do have some more information to supply though.
It appears the registration system is sending the the verify command. The problem appears to be the reply it gets.
It is getting a reply of $RETCODE=1$
It gets the same return code even if you put in false details which is why i am leaning towards an issue with how windows 8 is sending the HTTP request to verify.
I hope this helps someone.
EDIT: Upon further investigation. The SDActivate.lng file reports response code one is missing arguments.
Therefore it would appear the activation software isn't forming the proper request/ not inserting login details into the verify request.