Flash CS5 AS3 Preloader Issues

Question

Hi.
I'm a complete novice with Flash and at risk at looking like 'Dumbest Poster of the Year', I'm requesting help/advic over a couple of issues.
My first concern is with a very simple preloader I've made for a movie. Here is the code (posted in first frame of movie; nothing else is in the frame except for the preloader itself):
import flash.events.Event;
stop();
addEventListener(Event.ENTER_FRAME, loaderF);
function loaderF(e:Event):void{
var toLoad:Number = loaderInfo.bytesTotal;
var loaded:Number = loaderInfo.bytesLoaded;
var total:Number = loaded/toLoad;
if(loaded == toLoad) {
  removeEventListener(Event.ENTER_FRAME, loaderF);
  gotoAndPlay(2);
} else {
  PreLoader.PreLoaderFill.scaleX = total;
  PreLoader.PercentLoaded.text = Math.floor(total*100) + "%";
When I simulate a download, the preloader works fine in all the settings except for 'T1'. On this setting, the movie loads to about 20% then the preloader stops, the movie begins and I receive the following error message in the output panel:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at FlashFront1_fla::MainTimeline/loaderF() .
The movie itself plays fine on all settings, including 'T1'. Debug doesn't report any issues on preloader or movie.
Can anybody give me any idea what the source of the issue is? Should I even be concerned about it givne that the movie plays without a problem?
My second question relates to the 'Simulate Download' pre-settings in Flash. I know their are people out there still on 56K dial-up, or with 'broadband' running at 500 KBS (in the UK at least), but nevertheless, the download simulation settings seem like they are all geared to internet as it was in 1997 and are hardly reflective of the capacity of modern connections. Why is this?
My movie is not large (about 320KB). Should I even be bothering with a preloader or am I wasting my time for a small minority audience (much like the web designers who still produce sites for the 12 people in the world still browsing in 800 x 600 res)?
Thanks for any help/advice.

Answer 1

Flash movies stream down and finish "loading" when the first frame and content that loads on the first frame is available, though frame 1001 might not be downloaded yet. You would think you'd be kinda safe with frame 2 on a T1, but I think the issue is things aren't updating in the right order  rather than things not really being downloaded. Heck, it could even just be the T1 simulation that's causing problems.
Debug Movie probably isn't showing issues because it slows the timing enough to make everything ok. You could try trace statements too to see how far the code gets.
Also, you might try a full scale AS3 loader like this one http://www.republicofcode.com/tutorials/flash/as3loader/
I've found the Event.COMPLETE listener for the loader like this:
my_loader.contentLoaderInfo.addEventListener(Event.COMPLETE, finishLoading);
to be pretty accurate so far in regards to content truly being loaded where as previous methods gave false positives for loading.