Updated my post with the last smf 2.1 beta 2, and everything works fine, but anyone can register, to try to fill it and send receive the following error:
http://www.tectonny.com.br/forum/index.php?action=signup2
You are not allowed to access this section
Can test here: http://www.tectonny.com.br/forum/index.php?action=signup
Managed to solve, the error occurs when we activate the Verification Questions and do not put the issues.