Actionscript 3 :: Convert Global Coordinates To Local Coordinates Of A UIComplenent In Flex Project?

I was trying to convert global coordinates to local coordinates of a UIComplenent in my flex project using below code using below code

var gp:Point = new Point(e.stageX,e.stageY); //global point
var lp:Point = uic.globalToLocal(gp); //local point

uic is UIComponent in which I have subclass of Sprite for drawing something I have set the sprite's mouseEnabled and mouseChildren to false to not interrupt the mouse event. above code is within uic's mousemove event where I was tracing the gp and lp gp was giving correct value and suprisingly lp was giving negetive values. when I move the move to the top left corner of uic i expect lp to be 0,0 but it is giving the -width of of uic. I broke my head for hours and ended up finding an alternate by using offsets. Infact my original code was much simpler like this which was same issue

var lp:Point = new Point(e.localX,e.localY);

I am not sure what exactly is causing this problem. the workaround had lot of issues and it creating a mess in my rest of the algorithms.Just now I found even more interesting thing (which is actually weird). for some reason I went and create a new lp2

var lp2:Point = new Point(e.localX,e.localY);

now surprisingly it was giving correct values as expected and I went back and changed the code as

var gp:Point = new Point(e.stageX,e.stageY); //global point
var lp:Point = uic.globalToLocal(gp); //local point
var lp2:Point = new Point(e.localX,e.localY);
var lp2:Point = uic.globalToLocal(gp);

now it is expected to have all the lp, lp2 and lp3 variables to be same but weiredly lp two is giving wrong value and lp2 and lp3 were giving correct. I am suspecting using the variable lp has something to do. I am not sure about that but above proves it so right now I am using lp2.