Facebook page, HTTP VERB not allowed, How to receive POST for my IFRAME?

Our facebook page is saying:

Error Summary HTTP Error 405.0 - Method Not Allowed The 开发者_Python百科page you are looking for cannot be displayed because an invalid method (HTTP verb) is being used.

I've checked Firebug and its sending a POST request to our .html file, which I'm guessing can't receive it? Does anyone know how I get around this problem? I'm hosting on ASP.NET 4.

Thanks!

Change your page tab URL to be a URL which can accept POST requests

This POST request from Facebook includes information which tells you the current page ID, if the user likes the page, etc ( see https://developers.facebook.com/docs/authentication/signed_request/ 's page parameter) which can't be safely passed in a GET request