setInterval Scoping issue

I have created a number of Movieclips as part of my Navbar such as About Us, Contact etc. I’m using setInterval to send them to a function that springs them open one after another using the tween class. The they are dynamically generated and positioned using the following code, however when I want to use them as buttons by using onRollOver or onRelease they act like I’m not scoping them correctly. In other words the cursor does not change into a hand when over them. This is a setInterval issue as if I have them open just using attachMovie, the scoping works just fine. Can anyone give me tell me where I’m going wrong, or a better way to do this. The actual code is as follows:

function aboutUs () {
var mcAboutUs:MovieClip = this.attachMovie("mcAboutUs", "aboutUs_mc", 20, {_x:197, _y:520});
var x_elasticTween:Tween = new Tween (aboutUs_mc,"_xscale",Elastic.easeOut,0,100,1,true );
var y_elasticTween:Tween = new Tween (aboutUs_mc,"_yscale",Elastic.easeOut,0,100,1,true );

function setIntervals() {
_global.intervalID1 = setInterval(this, "aboutUs", 1000);
//There are more in here, each going to its own function to attachMovie and Tween them. 
//This all works fine.



this.aboutUs_mc.onRelease = function() { // OnRelease is suppose to activate another function that generates the "About Us" page but nothing happens as if the instance is not been scoped.

Could someone also tell me how to embed this code in it’s own window in these threads also.

Thanks for your help,