I had set the password mini length to 4 by edit the register.php in line 241 :
if (utf_strlen($password) < 4) $error .= '<li>' . $lang_register_php['err_password_short'];
I test to input the password "11" it still allow me to change the password and, until I enter "1" it will return the error say that the password is too short. Anything wrong with the code ?