Selfreg - email verification form don't work

[seadragon]

i've installed Selfreg.

All works perfectly except the email verification form (linked in the verification email)
When user insert the password and press submit to validate the account, the page is reloaded without any result. so the user should re-insert validation code and password... and this forever.
No message returned and NO confirmation of account activated mail are sent.

example
http://***.myhost.com/Selfreg/confirm/61/TM6RPBGXM6/2/myemail@myhost.it

after submit the page is reloaded and redirected to

http://***.myhost.com/registrati
(that is the page with id 61)

how can i solve this?