Yessir . . . when I remove it as my document class and try to import it on the timeline using this:

//--------------------------

  import fladev.twitter.MainClass;

            var twitterReader:MainClass = new MainClass();

//--------------------------

I still get a no twitter info and I get this in my output:

//--------------------------

TypeError: Error #1085: The element type "link" must be terminated by the matching end-tag "</link>".

          at fladev.twitter::MainClass/displayInfo()[myfolder\src\MainClass.as:56]

          at flash.events::EventDispatcher/dispatchEventFunction()

          at flash.events::EventDispatcher/dispatchEvent()

          at flash.net::URLLoader/onComplete()

//--------------------------

Not sure if this helps or adds to the confusion.

Okay, so I made the changes you suggested and now I get a bunch of "1180: Call to a possibly undefined method gotoAndStop" errors, which completely baffles me.  My swf won't generate because of these errors so I don't know how the changes have effected my fla.

So I decided to try to put my twitterReader in a MovieClip. MainClass is no longer my document class and is now linked instead to my twitterReader MovieClip extending it to a Sprite and I now get the same error as before with this:

TypeError: Error #1085: The element type "link" must be terminated by the matching end-tag "</link>".

          at fladev.twitter::MainClass/displayInfo()[myfolder\src\MainClass.as:56]

          at flash.events::EventDispatcher/dispatchEventFunction()

          at flash.events::EventDispatcher/dispatchEvent()

          at flash.net::URLLoader/onComplete()

Yeah, I was getting that "1180: Call to a possibly undefined method gotoAndStop" error.

Nope, no problems at all.  I can get it to pull my twitter feeds and everything. Problems begin occurring when I try to use it in another project, whether it be on a different frame on the timeline, a different scene etc.  I can load the twitreader swf in my project with no problems as well. But because I am trying to use this in an iOS app I'm building I can't load it because ti has script to it so it has to be contained in the main as best as I can tell.

Alright, so I re-downloaded the sample files, I changed this part MainClass code:

private function displayInfo(e:Event):void

        {

            var _root:MovieClip = MovieClip(this.root);

            xml = new XML(e.target.data);                  

            _root.content_txt.htmlText = getContent(1) +  getContent(2)+ getContent(3) + getContent(4);  

            //trace(xml);

            //show some info about the user

            _root.info_txt.text = "Followers: " + xml.status[num].user.followers_count + "; " + "Following " + xml.status[num].user.friends_count + "; " + "Tweets " + xml.status[num].user.statuses_count + ";";

            //display the user account

            _root.name_txt.text = xml.status[num].user.screen_name;

            //create a loader for picture

            loader = new Loader();

            loader.load(new URLRequest(xml.status[num].user.profile_image_url));

            _root.addChildAt(loader, 1);

            loader.x = 116;

            loader.y = 102;

        }

I removed MainClass as the document class. and added this:

var mc:MainClass=new MainClass();

addChild(mc);

on the main timeline.

When I test this is what pops up in my Compiler Errors:

I put MainClass in the same folder as the fla (it was in a subfolder in the same directory) and I still get the 1180 and 1046 errors.  Just to confirm, I have this in the first frame of the timeline:

var mc:MainClass=new MainClass();

addChild(mc);

and here is what I have for MainClass:

package fladev.twitter

{

          import flash.display.Loader;

          import flash.display.Sprite;

          import flash.display.MovieClip

          import flash.events.Event;

          import flash.events.SecurityErrorEvent;

          import flash.net.URLLoader;

          import flash.net.URLRequest;

          import flash.text.TextField;

       public class MainClass extends Sprite

          {

                    public var content_txt:TextField;

                    public var posted_txt:TextField;

                    public var info_txt:TextField;

                    public var name_txt:TextField;

                    private static const USERNAME:String = "ctistechapps";

                    private static const URL:String = "http://preview.fladev.com/how-to-build-a-flash-actionscript-3-0-twitte r-widget/proxy.php?url=";

                    private static const REQUEST:String = URL + USERNAME;

                    private var urlLoader:URLLoader;

                    private var xml:XML;

                    private var loader:Loader;

                    private var num:Number = 1;//display first post info, you can use also ?count=5

                    public function MainClass() {

                              urlLoader = new URLLoader();

                              urlLoader.load(new URLRequest(REQUEST));

                              urlLoader.addEventListener(Event.COMPLETE, displayInfo);

                              urlLoader.addEventListener(SecurityErrorEvent.SECURITY _ERROR, onSecurity);

                    }

                    private function onSecurity(e:SecurityErrorEvent):void

                    {

                    }

                    private function displayInfo(e:Event):void

        {

            var _root:MovieClip = MovieClip(this.root);  // assuming you add this class instance to the main timeline before loading is complete.

            xml = new XML(e.target.data);                  

            _root.content_txt.htmlText = getContent(0) +  getContent(1)+ getContent(2) + getContent(3);  

            //trace(xml);

            //show some info about the user

            _root.info_txt.text = "Followers: " + xml.status[num].user.followers_count + "; " + "Following " + xml.status[num].user.friends_count + "; " + "Tweets " + xml.status[num].user.statuses_count + ";";

            //display the user account

            _root.name_txt.text = xml.status[num].user.screen_name;

            //create a loader for picture

            loader = new Loader();

            loader.load(new URLRequest(xml.status[num].user.profile_image_url));

            _root.addChildAt(loader, 1);

            loader.x = 116;

            loader.y = 102;

        }

                    private function getContent(num:Number) {

                              //show just month, day and hour

                              var posted:String = xml.status[num].created_at;

                              var content:String = "<font color='#224466'><a href=" + '"http://twitter.com/' + USERNAME + "/statuses/" + xml.status[num].id + '" target="_blank">' + xml.status[num].text + "</a></font><br/><font size='9'>" +"Posted on: " + posted.substr(0, posted.length - 11) + "; " + "From: " + xml.status[num].source + "</font><br/><br/>";

                              //return all info

                              return content;

                    }

          }

}

Done, but I am still getting the 1046 and 1180 errors.

HOLY FREAKIN' AWESOME!  Yes!  It now works in my other fla as well!  Thank You! Thank You! Thank You!  So, kglad, what was it that I was doing wrong?  I can't help but to be a little perplexed at the turn of events.

Thanks again for all your help!