Captcha not working in Facebook app

I have an page thats using CAPTCHA and works fine on my servers but when I access the page through a Facebook page tab app the captcha doesn't work. Any ideas? Thanks in advance for the help! -- You received this message because you are subscribed to the Google Groups "reCAPTCHA" group. To unsubscribe from this group and stop receiving emails from it, send an email to recaptcha+unsubscribe@googlegroups.com. To post to this group, send email to recaptcha@googlegroups.com. Visit this group at http://groups.google.com/group/recaptcha. For more options, visit https://groups.google.com/groups/opt_out.