[twitter-dev] PIN Authentication Examples?

[DWRoelands]

I'm having a devil of a time getting my application to connect to
Twitter via OAuth and the six-digit pin method.

I've been working with the excellent OAuth library from
ShannonWhitley:
http://www.voiceoftech.com/swhitley/?p=681

I'm able to get an authorization link, open a browser, and get the six-
digit PIN.  However, I can't seem to submit that PIN back to Twitter
without getting a 401 Unauthorized error.

I added this method to Shannon's TWitter OAuth code:

        public bool ValidatePin(string PIN)
        {
            string response = WebRequest(Method.GET, string.Format
("{0}?oauth_verifier={1}", ACCESS_TOKEN, PIN), string.Empty);
            if (response.Length > 0)
            {
                //Store the Token and Token Secret
                var qs = HttpUtility.ParseQueryString(response);
                if (!string.IsNullOrEmpty(qs["oauth_token"]))
this.Token = qs["oauth_token"];
                if (!string.IsNullOrEmpty(qs["oauth_token_secret"]))
this.TokenSecret = qs["oauth_token_secret"];
                return true;
            }
            else
            {
                return false;
            }
        }

Inevitably, I get 401 Unauthorized when submitting the
"oauth_verifier" web request.
I have a consumer key and a consumer key secret which work (as is
evidenced by the fact that I can get an authorization link).

Has anyone else encountered similar issues, or does anyone else have
any guidance on this particular issue?

Thanks in advance.
--Duane