Registration page: Resetting entered password to incorrect value if user enter type incorrect captcha value

Steps to reproduce
1. Enable Captcha plugin
2. Sing Up for new user from registration page http://uat.jtalks.org/jcommune/user/new (not pop-up dialog)
3. Fill name, email, password, repeat password fields with correct values
4. Enter incorrect Captcha value and click on "Sign Up" button
Note, that Password seems to be changed to some default value
5. Enter correct Captcha value and click on "Sign Up" button again

Actual result Notification error "Password and confirmation password do not match" on step 5
Expected result Password should be not reset, if user did Captcha mistake.