Too many failed verifications

We're using google recaptcha v2 on our site. For a given day there are 99 succesful verifications and 103 with opposite response (captchaResponse.success=false). Don't you think that the number of failed responses is too high as for simple one click verification method? I wonder if there is different explanation of these statistics - some problem with google mechanism itself or sth else. Any idea? Regards, - ms -- 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://bit.ly/1dkFnYd. For more options, visit http://bit.ly/P65DvS.