reCaptcha accepts wrong answers sometimes

Question

We are using recaptcha ASP.NET control:

http://recaptcha.net/plugins/aspnet/

However, we find that in some situations, recaptcha accepts answers which are clearly wrong.

For example, recaptcha provided these words:

of purser

The tester typed in the following:

o purser

..but Page.IsValid returned true! Is this a known issue with recaptcha?

Answer 1

found my answer:

http://wiki.recaptcha.net/index.php/FAQ#reCAPTCHA_is_accepting_incorrect_words