Estou seguindo muitas instruções para criar um tweet simples no meu aplicativo. Já o registrei no Twitter, mas não consigo fazer um tweet. Posso fazer login, mas não atualizar meu status. Aqui está o código para fazer login

private void twitterLogOn() {
        Twitter twitter = new TwitterFactory().getInstance();
        try {

            twitter.setOAuthConsumer(consumerKey, consumerSecret);
            rToken = twitter.getOAuthRequestToken(myCallBack);
            startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(rToken.getAuthenticationURL())));
        } catch (IllegalStateException e) {
            // access token is already available, or consumer key/secret is not
            // set.
            if (!twitter.getAuthorization().isEnabled()) {
                System.out.println("OAuth consumer key/secret is not set.");
                finish();
            }
        } catch (Exception e) {
            Toast.makeText(Configuration.this,getString(R.string.networkError), Toast.LENGTH_SHORT).show();
        }
    }

Isso parece funcionar bem, mas quando eu voltar ao meu aplicativo após o login, esse próximo código deverá ser executado, terminando sempre na exceção Toas

public void onResume() {    
        super.onResume();

        Uri uri = getIntent().getData();

        if (uri != null) {    
            oauthVerifier = uri.getQueryParameter("oauth_verifier");

            try {    
                Twitter tt = new TwitterFactory().getInstance(); // Do I need this new twitter instance?
                tt.setOAuthConsumer(consumerKey, consumerSecret);
                AccessToken at = tt.getOAuthAccessToken(rToken, oauthVerifier); // Gives the error

                       // Do tweet here ...

                } catch (Exception e) {
                    Toast.makeText(Configuration.this, "Network Host not responding",Toast.LENGTH_SHORT).show();
                }
            }
    }

Qualquer olho de falcão bom lá que possa me dizer o que estou fazendo de errado? Esta é a linha que dispara a exceção

AccessToken at = tt.getOAuthAccessToken(rToken, oauthVerifier);

Desde já, obrigado

EDITA

Stack Trace: (leia em algum lugar isso está apenas ocultando um erro 401)

07-24 12:49:31.931: WARN/System.err(18441): Received authentication challenge is nullRelevant discussions can be on the Internet at:
07-24 12:49:31.931: WARN/System.err(18441):     http://www.google.co.jp/search?q=9ddbeb3a or
07-24 12:49:31.931: WARN/System.err(18441):     http://www.google.co.jp/search?q=5c9c15a6
07-24 12:49:31.931: WARN/System.err(18441): TwitterException{exceptionCode=[9ddbeb3a-5c9c15a6 c8a7b39b-36e69ae1], statusCode=-1, retryAfter=-1, rateLimitStatus=null, featureSpecificRateLimitStatus=null, version=2.2.3}
07-24 12:49:31.931: WARN/System.err(18441):     at twitter4j.internal.http.HttpClientImpl.request(HttpClientImpl.java:204)
07-24 12:49:31.931: WARN/System.err(18441):     at twitter4j.internal.http.HttpClientWrapper.request(HttpClientWrapper.java:65)
07-24 12:49:31.931: WARN/System.err(18441):     at twitter4j.internal.http.HttpClientWrapper.post(HttpClientWrapper.java:102)
07-24 12:49:31.931: WARN/System.err(18441):     at twitter4j.auth.OAuthAuthorization.getOAuthAccessToken(OAuthAuthorization.java:142)
07-24 12:49:31.931: WARN/System.err(18441):     at twitter4j.auth.OAuthAuthorization.getOAuthAccessToken(OAuthAuthorization.java:160)
07-24 12:49:31.931: WARN/System.err(18441):     at twitter4j.TwitterBaseImpl.getOAuthAccessToken(TwitterBaseImpl.java:349)
07-24 12:49:31.931: WARN/System.err(18441):     at com.my.app.TwitterTweetActivity.onResume(TwitterTweetActivity.java:76)
07-24 12:49:31.931: WARN/System.err(18441):     at com.my.app.TwitterTweetActivity.onResume(TwitterTweetActivity.java:64)
07-24 12:49:31.931: WARN/System.err(18441):     at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1149)
07-24 12:49:31.931: WARN/System.err(18441):     at android.app.Activity.performResume(Activity.java:3833)
07-24 12:49:31.931: WARN/System.err(18441):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2215)
07-24 12:49:31.941: WARN/System.err(18441):     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2240)
07-24 12:49:31.941: WARN/System.err(18441):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1773)
07-24 12:49:31.941: WARN/System.err(18441):     at android.app.ActivityThread.access$1500(ActivityThread.java:123)
07-24 12:49:31.941: WARN/System.err(18441):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:936)
07-24 12:49:31.941: WARN/System.err(18441):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-24 12:49:31.941: WARN/System.err(18441):     at android.os.Looper.loop(Looper.java:123)
07-24 12:49:31.941: WARN/System.err(18441):     at android.app.ActivityThread.main(ActivityThread.java:3812)
07-24 12:49:31.941: WARN/System.err(18441):     at java.lang.reflect.Method.invokeNative(Native Method)
07-24 12:49:31.941: WARN/System.err(18441):     at java.lang.reflect.Method.invoke(Method.java:507)
07-24 12:49:31.941: WARN/System.err(18441):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
07-24 12:49:31.941: WARN/System.err(18441):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
07-24 12:49:31.941: WARN/System.err(18441):     at dalvik.system.NativeStart.main(Native Method)
07-24 12:49:31.941: WARN/System.err(18441): Caused by: java.io.IOException: Received authentication challenge is null
07-24 12:49:31.941: WARN/System.err(18441):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.processAuthHeader(HttpURLConnectionImpl.java:1153)
07-24 12:49:31.941: WARN/System.err(18441):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.processResponseHeaders(HttpURLConnectionImpl.java:1095)
07-24 12:49:31.951: WARN/System.err(18441):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.retrieveResponse(HttpURLConnectionImpl.java:1048)
07-24 12:49:31.951: WARN/System.err(18441):     at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:726)
07-24 12:49:31.951: WARN/System.err(18441):     at twitter4j.internal.http.HttpResponseImpl.<init>(HttpResponseImpl.java:35)
07-24 12:49:31.951: WARN/System.err(18441):     at twitter4j.internal.http.HttpClientImpl.request(HttpClientImpl.java:168)
07-24 12:49:31.951: WARN/System.err(18441):     ... 22 more

API para o método: getOAuthREquestToken