Hi - having the same issue here.
I originally posted today that the email was not being sent because the progress indicator in Firefox (win) just kept spinning.
So I turned off Ajax on the form and it worked fine in Safari (as did the previous method) but on FF and other browsers I get the same message that Gavin had - invalid token.
Please advise - as I said the component works fine in Safari for mac, and our site works fine with www. or without www. in front of the address.
testing.sexcereal.com/
Please advise.