php - Recaptcha with magento -

I have installed a reCAPTE in my client's site that is not yet but in development ReCAPTO is working fine till last week , But when I see it, it returns "Input error: invalid referrer" instead of the ReCAP block. I'm just wondering what could be the reason for this. Is it something to do with public and private key ?? Any help would be appreciated

Cheers

Yes! It's working for me, I manage 3 different domains and I was trying to use the same reCaptcha keys, I get this error "Input Error: Invalid Refferer"

< P> I just do my every domain and it works like a charm!