excellent code! THANK YOU!!!

http://subashflash.blogspot.com/2010/08/rotation-of-object-based-on-center.html

This approach has one disadvantage – the rotation is always relative to the previous rotation and after a large number of iterations rounding error is accumulated. A possible solution can be found here:

http://itforum.webrichservices.com/viewtopic.php?f=127&t=14

Thank you for your original posing anyway, it helped me to understand a bit better how Flash works…

package
{
import flash.display.Sprite;
import flash.events.Event;
import flash.geom.*;

/**
* …
* @author tomas.teicher
*/
public class Main extends Sprite
{
public var rect:Sprite;
public var bod:Point;

public function Main():void
{
if (stage) init();
else addEventListener(Event.ADDED_TO_STAGE, init);
}

private function init(e:Event = null):void
{
removeEventListener(Event.ADDED_TO_STAGE, init);
// entry point
rect = new Sprite();
rect.graphics.beginFill(0x00ff00);
rect.graphics.drawRect(0, 0, 100, 100);
rect.graphics.endFill();
addChild(rect);

bod = new Point(rect.x + rect.width/2, rect.y+rect.height/2);
addEventListener(Event.ENTER_FRAME, this.enterFrameHandler);

}

private function rotateAroundCenter (ob:*, angleDegrees:Number, ptRotationPoint:Point):void {
var m:Matrix=ob.transform.matrix;
m.tx -= ptRotationPoint.x;
m.ty -= ptRotationPoint.y;
m.rotate (angleDegrees*(Math.PI/180));
m.tx += ptRotationPoint.x;
m.ty += ptRotationPoint.y;
ob.transform.matrix=m;
}

function enterFrameHandler(event:Event):void {
rotateAroundCenter (rect, 1, bod);
}
}

}