I have tested both and can't perform a registration.
Internal question says: The CAPTCHA solution was incorrect
Recaptcha says: We couldn't contact the reCAPTCHA server to verify your answer. Please try again.
Using
joomla: 3.4.5
cb: 2.0.11
cb antispam: 2.0.0
Registration Fields:
Name
Email
Username
Password
Verify Password
Country (required)
City (required)
Terms and Conditions
Captcha (cb antispam)
Receive (Acymailing)