ActionScript 2.0 :: Using SetInterval With MovieClips - Instance Not Been Scoped

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.

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 );
clearInterval(_global.intervalID1);
} 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.

setIntervals();
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.
page_aboutUs();
}