I cannot get the RPX auth_info API call to work. It keeps returning the error: "Missing parameter: apiKey" I am using the C# RPX Helper Class provided on their Wiki:RPX Helper Class

Below is my code in my Page_Load method. The RPX service works by sending a POST to a Url that I specify. My code gets the token from the post data shown below. Then I call the AuthInfo API method.

string token = Request.Params["token"];
string apiKey = "xxxxxxxxxxxxxxx"; //my API key
Rpx rpx = new Rpx(apiKey, "http://rpxnow.com");
XmlElement xmlElement = rpx.AuthInfo(token);

Everything looks good. The token is populated. Within their code, the "apiKey" value pair is added to the post data written to the Request stream. Has anyone had luck with this? Any ideas why this is not working? Thanks.