Flash - coordinates keeps reseting to 0 - actionscript-3

Question

ok I can't make this work no matter what, it keeps resetting coordinates to 0.
I make a ship object on stage and make a class of that ship.
public class Ship extends MovieClip {
private var speedX;
private var speedY;
public function Ship() {
x = 50;
y = 150;
trace(x, y);
stage.addEventListener(KeyboardEvent.KEY_DOWN ,keyDown);
stage.addEventListener(KeyboardEvent.KEY_UP ,keyUp);
stage.addEventListener(Event.ENTER_FRAME, update);
}
public function keyDown(e:KeyboardEvent) {
if(e.keyCode == 37) {
speedX = -5;
}
if(e.keyCode == 38) {
speedY = -5;
}
if(e.keyCode == 39) {
speedX = 5;
}
if(e.keyCode == 40) {
speedY = 5;
}
}
public function keyUp(e:KeyboardEvent) {
trace (x,y);
if(e.keyCode == 37 || e.keyCode == 39) {
speedX = 0;
}
if(e.keyCode == 38 || e.keyCode == 40) {
speedY = 0;
}
}
public function update(e:Event) {
x += speedX;
y += speedY;
}
}
here I set coordinates to 50, 150, the trace shows it right, but it still doesn't work.
the game is working fine except coordinates, what am I doing wrong?

Answer 1

Not sure that this will help, but I would explicitly set the update speed to 0 in the Ship() function.
I would also set the position, based on where you placed it, so that you can just place it in the scene, and then it will start from that location.
public function Ship() {
speedX = 0
speedY = 0
trace(x, y);
stage.addEventListener(KeyboardEvent.KEY_DOWN ,keyDown);
stage.addEventListener(KeyboardEvent.KEY_UP ,keyUp);
stage.addEventListener(Event.ENTER_FRAME, update);
}

Answer 2

I've tested this code on my machine and it works fine. Are there any parts of the code that you're not including?
I also changed the class to accept the main stage object as a parameter. This might solve the problem you're having:
public function Ship(pStage:DisplayObjectContainer):void
{
x = 50;
y = 150;
trace(x, y);
pStage.addEventListener(KeyboardEvent.KEY_DOWN, keyDown);
pStage.addEventListener(KeyboardEvent.KEY_UP, keyUp);
pStage.addEventListener(Event.ENTER_FRAME, update);
}
Wherever you initialize the Ship object, make sure you're passing the stage object from your Main class. This has worked for me with all of my AS3 projects.