MC tween / Array.prototype incompatibility

Hello people!
I’m a Swishmax user and I’ve converted the XML search tutorial from Kirupa to swishmax2 (Found it here )
As some of you might know, Swishmax is also a flash tool, that allows AS2.0.
Flawlessgod converted MCtween for use in swishmax, but there’s something going on with the Array.prototype that don’t allow me to give “late” actions (don’t know the real name for it… I mean… fire an action after the tween is complete.
This don’t let me give “late” actions to objects:

Arrays.prototype.contain = function(searchValue){
var i = this.length;
while(i--) if (this* == searchValue) return true;
return false;
};

If I have this action:

myMovieObject.scaleTo(200, 1, "linear", 0, function(){
_root.test.gotoAndPlay(2);
})

It will only scale the object, and doesn’t plays the finished action!
However… If I rename " Array.prototype.contain " to "Arrays.prototype.contain " it works just fine, but obviously the other function stops working!

Can someone please tell me how to solve this problem?
In the attachment you can find swishmax file, and the *.sm2 file (open with notepad or something)

Thanks in advance!