Mouse.hide(); does not work - mouse cursor is still shown

programming flash
1

why mouse cursor does not hide ?
the mc cursor to replace mouse cursor is shown together with it;
what´s wrong?
thanks

onLoad = function () {
Mouse.hide();
cursor.swapDepths(200);
};

onEnterFrame = function () {
cursor._x = _xmouse;
cursor._y = _ymouse;
};

onUnload = function () {
Mouse.show();
};