Recaptcha returning "The reCAPTCHA server is unavailable"

Question

Hi,

I'm using ASP.NET and plugging in the google Recaptcha user control successfully, when calling the IsValid method on it, it returns in its recaptcha.ErrorMessage property: "The reCAPTCHA server is unavailable" and recaptcha.IsValid obviously returns false.

Does anyone know the reason why this could happen? Is it because I'm working on my localhost (Setup private and public keys on my localhost) and this sits on my work network? I suspect the google server that serves Recaptcha isn't down as its serving new Captcha words everytime I refresh.

Any help would be appreciated. Thanks