ActionScript 2.0 :: News Scroller - Center Justifying Dynamic Text

I have this news scroller for work - Vertical member (160 X 600) And the idea is that it has 3 text fields (Headlines). These fields are lined up vertically (one at the top of the scroller, one at the middle, and one at the bottom.). I load them dynamically from XML, and after about 5 seconds, I have them all move up. (the top one goes up the top, and comes back from the bottom, the other two move up). The problem is that I am trying to center justify them. When they're loaded I can center justify them, using this code:

Code:
MovieClip.prototype.centerFunction = function() {
format = new TextFormat();
format.align = "center";
_root.news2.headline2_txt.setTextFormat(format);
_root.news3.headline3_txt.setTextFormat(format);
_root.news1.headline1_txt.setTextFormat(format);
}

Now, when they are first center justified by the code, they look slightly off, and once they move they arrange themselves correctly.