Actionscript tweening - desperately need some direction

So I decided to dive into tweening using actionscripting. I began by just using simple tween commands such as:

new Tween (button1_mc, "x", Strong.easeInOut, button1_mc.x, 32.6, 30, false);
new Tween (button1_mc, "alpha", Regular.easeIn, 0, 1, 30, false);
new Tween (button2_mc, "x", Strong.easeInOut, button2_mc.x, 137.9, 30, false);
new Tween (button2_mc, "alpha", Regular.easeIn, 0, 1, 30, false);

However, after my file got more involved, I had problems with tweens stopping in the middle of the animation or not starting at all both when I tested my movie in flash and when I viewed it in browsers. After doing a little digging, I found that this is common to AS3 if you don’t handle the animation correctly. I found this code snippet and tried to apply it to for my purposes:

private var earrings1Tween:Array = [];
private function startEarings1Tweens():void
	var earrings1Tween:Tween = new Tween (earrings1_mc, "x", Strong.easeInOut, earrings1_mc.x, 32.6, 30, false);
	var earrings2Tween:Tween = new Tween (earrings2_mc, "x", Strong.easeInOut, earrings2_mc.x, 32.6, 30, false);
	tween.earrings1Tween.addEventListener(TweenEvent.MOTION_FINISH, motionFinishHandler);
	this.earrings1Tween.push( tween );

private function motionFinishedHandler (event:TweenEvent):void
	var tween:Tween = Tween(event.tager);
	tween.removeEventListener(TweenEvent.MOTION_FINISH, motionFinishHandler);
	var index:int = this.earrings1Tween.indexOf(tween);
	this.earrings1Tween.splice(index, 1);

Using this method, I get the error message “1013: The private attribute may be used only on class property definitions.” I realize it has something to do with classes but I’m not even sure where to start when taking this approach to tweening.

I have also looked into tweening engines such as TweenLite. I understand the methodology behind these types of engines but I’m just wondering if I have to apply the same type of functionality (creating Arrays etc) as I do when using the default Flash tweening method (which I’m not very clear on).

The bottom line is I’m just trying to find the most efficient and effective way to apply multiple tweens, that occur simultaneously, to several different objects…and in some cases, apply different tweens to the one object at the same time. The site in question can be seen here. The animations that I’m referring to occur when you click on each navigation button. There should be a container that animates in along with six thumbnail images. As I said before, sometimes the animation works perfectly and sometimes it gets halfway through and stops.

Any advice or direction would be greatly appreciated!