android - No Authentication challenge found

I read a lot about this issue but I was not able to figure it out. I am using HttpURLConnection and it works fine, but on JellyBean where it throws the IOException: No Authentication challenge found when I call getResponseCode() in case of 401 even though the backend is sending in the response the correct headers:

HTTP/1.1 401 Unauthorized
WWW-Authenticate: realm="realm" 

On the other hand, debugging it, I experienced something strange. I printed the headers value out on the console this way:

    Map> map = connection.getHeaderFields();
    if (map != null) {
            Set set = map.keySet();

            for (String tmp : set) {
                Log.i(LOG_TAG, tmp != null ? tmp : "null");
            }
    }

just before calling connection.getResponseCode(); and it stopped to throw that exception.

Any clue?

The connection is set up with the following values:

    connection.setDoInput(true);
    connection.setDoOutput(true);     
    connection.setRequestProperty("Content-type", "application/x-www-form-urlencoded; charset=utf-8");
    connection.setRequestProperty("Accept", "application/json");
    connection.setRequestProperty("Accept-Charset", "utf-8");
    connection.setRequestProperty("Accept-Encoding", "gzip");