Unity 4x Set.Active warnings

I upgraded to unity 4.0 and I get a lot of warnings and possibly from that, mac appstore validation fails. I am activating/deacivating a couple of game objects with this

#pragma strict

public var blackScreen : GameObject;
var lightSwitchObject : GameObject;
var lightOnSound : AudioClip;
var lightOffSound : AudioClip;

var LIGHTON : GameObject;
var LIGHTOFF : GameObject;

function Start(){
	blackScreen.animation.Play("Alpha0");
    LIGHTON.SetActiveRecursively (true);
    LIGHTOFF.SetActiveRecursively (false);
}

function fadeIn(){
    blackScreen.animation.Play("Alpha0");
}

function fadeOut(){
    blackScreen.animation.Play("Alpha255");
}

function DarkRoom()
{
	fadeIn();
	lightSwitchObject.active = false;
	audio.PlayOneShot(lightOnSound);
	LIGHTON.SetActiveRecursively (true);
    LIGHTOFF.SetActiveRecursively (false);
}

function LightRoom()
{
	fadeOut();
	lightSwitchObject.active = true;
	audio.PlayOneShot(lightOffSound);
	LIGHTON.SetActiveRecursively (false);
    LIGHTOFF.SetActiveRecursively (true);
	
}
function DarkRoomDummy()
{
	lightSwitchObject.active = false;
}

function LightRoomDummy()
{
	lightSwitchObject.active = true;
}

and the warning is like this:

Assets/Scripts/NewCameraFadeBlack.js(28,27): BCW0012: WARNING: ‘UnityEngine.GameObject.active’ is obsolete. GameObject.active is obsolete. Use GameObject.SetActive(), GameObject.activeSelf or GameObject.activeInHierarchy.

EDIT

for this particular case I can probably use instantiate and destroy and forget about active inactive for now. The problem is that I cannot understand (read the docs) for the life of me how to check if a child object is active.

private function HasChildren(obj:Transform)
	{
		var active:int = 0;
		for (var _child:Transform in obj)
		{
			if (_child.gameObject.active == true)
				active++;
		}
		return (active > 0);
	}

if (_child.gameObject.active == true) - I need to check if the current set of targets are active (they are parented to a game object used to activate that particular set).

Now, in Unity 4, if you want to activate a game object, you have to do myGameObject.SetActive(true) - the same to deactivate, passing false.

To check if a game object is active or not, just do

if (myGameObject.gameObject.activeSelf == true) //Do what you need

SetActive
activateSelf