Sign Up: password changed on registering user from sign up page

If some value is not correct and you are clicking "Sign up", the password in the appropriate field does not retain its previous value.

Steps to reproduce
1. Open registration form in the new tab (http://qa.jtalks.org/jcommune/user/new)
2. Fill valid data in the all fields except capture.
3. Click "Sign up"

Actual result: password is changed: if you fill image text with the value from image and try to register again, error about password field appears.
Expected result: field with password is not changed