24media on "[Plugin: Contact Form 7] Don't show success message"

Hello,
this is the page where i used CF7
http://www.letscakemodena.it/contest-facebook/
If you compile the form and you click on "invia la tua foto" (submit) don't show success message.

With Firebug i tried to see any JS errors, but it seems OK.

By the way, i used CF7 also here: http://www.letscakemodena.it/ in the sidebar and it work fine.

Could anyone help me?
Thank you!

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