merlin_ulg on "Contact Form 7 not work with Real Simple Captcha"

I have latest Worpress and plugins Contact Form 7 and Real Simple Captcha. Form without captcha works fine, with captcha dont work, mail reached mailbox, but on form after click to button Send nothing happens.
It's madness, plugin Real Simple Captcha was written especially for Contact Form 7, but dont work!

http://wordpress.org/extend/plugins/contact-form-7/