ActionScript 3.0 :: Fade Effect Does Not Work As It Should

I'm trying to create a cursor that follows the mouse around and leaves a fading trail behind it, and know I would never put something so "1998" on my site, but I thought it would be fun to try and recreate one anyway for my own enjoyment. Okay this is the issue that I'm running into the fading ball cursor does actually work but for some odd reason after about 4 or 5 seconds it leaves a small trail behind it that does not fade all the way, it's almost as if code was resetting and starting all over by dropping the current execution of the code and starting over????

Here's my code. I'm using FLASH CS4 with all current updates
IMPORTED FILES
import fl.transitions.Tween;
import fl.transitions.easing.*;
stage.addEventListener(MouseEvent.MOUSE_MOVE, moveBall);
function moveBall(e:MouseEvent):void{
var ball:Ball = new Ball();
ball.x = mouseX;
ball.y = mouseY;
addChild(ball);
var fadAway:Tween = new Tween(ball, "alpha", Strong.easeOut, 1, 0, .5, true);
}