Hi! I love this plugin. That's why I wanted to report this thing I'm noticing: It is generating a lot of PHP errors. I'm running WP 3.9.1 on server with PHP 5.4.29 and this is found repeatedly in the errorlog at root folder:
[12-Jun-2014 02:36:06 UTC] PHP Warning: stripslashes() expects parameter 1 to be string, array given in /home/MYSITE/public_html/blog/wp-content/plugins/wp-conditional-captcha/wp-conditional-captcha.php on line 414
I'm sure is not critical, since it is still blocking the spam, but would be nice if the errorlog don't get flooded with this in several websites :)
Hope you can find the bug anytime soon.