Rating post doesn't work

If i try to rate a post in http://iosonodio.com it doesn't work. It's impossible to rate. Can you help me please?

I think that you should ask the K2 support team, because the AJAX request return a 404 error, so probably it is a problem with the rating script, which is beyond of our support - we are responsible for the K2 styling and we haven't enough knowledge to solve the K2 code-related problems.

ok thank you