Align loaded movieclip

[jAQUAN]

in frame one of your actions layer:

Stage.align = "LT"; //force the flash movie to justify to the top left
Stage.scaleMode = "noScale"; //prevent the movie from scaling its contents

resizeListener = new Object();//create a generic object
resizeListener.onResize = function(){  //give it a function for onResize events
blankMc._x = (Stage.width/2) - (blankMc._width/2); //assumes your registration point in the MC is top left
blankMc._y = (Stage.height/2) - (blankMc._height/2);//assumes your registration point in the MC is top left
}
Stage.addListener("resizeListener");

//any time you want to force an onResize call you can just say
resizeListener.onResize();