Orient mc to motion direction

Hi all,
I’m using the code bellow to move a movie clip to the mouse coordinates, wich are read on mouse down. The movieclip is facing the motion; the problem is: when it stops, it changes the rotation to increments of 45 degrees, and I would like to preserve the rotation the movieclip has during the motion. I just can’t figure it out…
Please help me if you can. Thank you!

 
function compDist ( fromX, fromY, toX, toY ){
 distX = toX - fromX;
 distY = toY - fromY;
 ret = Array(
    distX,
    distY
    );
 return ret;
 }
 
mc._x = 0;
mc._y = 0;
mc._rotation = 0;
mc.onMouseDown = function(){
 toX = _root._xmouse;
 toY = _root._ymouse;
 }
mc.onEnterFrame = function(){
 distArr = compDist(this._x, this._y, toX, toY);
  angleTo = Math.atan2(distArr[1], distArr[0]);
  //trace (angleTo);
  angleToDegs = angleTo * 180 / Math.PI;
  angleToDegs -= this._rotation;
  while (angleToDegs > 180) angleToDegs -= 360;
  while (angleToDegs < -180) angleToDegs += 360;
  this._rotation += angleToDegs/2;
 moveX = distArr[0]/2;
 moveY = distArr[1]/2;
 this._x += moveX;
 this._y += moveY;
}