Hi Andre.
Trying to use the plugin, but the problem as described above is still not solved:
When I try to send a message when I am logged in, I still get the validation error.
I use the following plugins:
Contact Form 7
WP-reCAPTCHA
Contact Form 7 reCAPTCHA extension
I also tried Better WordPress reCAPTCHA, but this has the same result.
WordPress version 3.4.1, so also up-to-date.
Please have a look into this issue again. For the time being, all visitors will have to be bothered by a captcha, which is still better than eternal error messages. For the rest, it all works like a charm.
Cheers