[twitter-dev] Setting user for statuses/show

[Dr. Drang]

I'm writing a Twitter webapp using jQuery. One of the features is the
ability to toggle the Favorite status of a tweet. The function looks
like this:

function toggleFavorite(msg_id) {
  $.getJSON("http://twitter.com/statuses/show/"; + msg_id + ".json",
    function(data){
      if (data.favorited) {
        $.post('http://twitter.com/favorites/destroy/' + msg_id +
'.json',
          {id:msg_id},
          function(post_return){
            $('#msg-' + msg_id + ' a.favorite').css('color', 'black');
          }
        );
      }
      else {
        $.post('http://twitter.com/favorites/create/' + msg_id +
'.json',
          {id:msg_id},
          function(post_return){
            $('#msg-' + msg_id + ' a.favorite').css('color', 'red');
          }
        );
      }
    }
  );
}

This used to work fine. But recently (I don't know when it started and
I don't know whether it's due to a change in the API or a change I
made elsewhere in my code) the "favorited" field began to always
return false, even if the tweet had been favorited by the user. The
getJSON call seems to be behaving like

    curl http://twitter.com/statuses/show/msg_id.json

instead of

    curl -u user:password http://twitter.com/statuses/show/msg_id.json

Is there some way to incorporate the user's Twitter ID into the
getJSON call to statuses/show?