Child Windows Can Not Access Window.opener When Multiple Child Windows Are Open

I have a parent window that pushes a new window object onto an Array
with the following code :

OpenChild()
{

//totalNumWindowsCreated is global

totalNumWindowsCreated = totalNumWindowsCreated + 1;
childWnds.push(window.open(link, "child" +
totalNumWindowsCreated,"dependent"));

..
..
..
}

This pops up a new window with every call. In the child window I call
a parent function onbeforeunload, appClose() :

function appClose(){

if (window.opener && !window.opener.closed){
window.opener.CloseChild(getQueryString("application"));
}}

This is in my frameset tag of the child code :

<frameset ... onbeforeUnload='appClose()'>

The window.opener.CloseChild() function is called perfectly when I have
one child window open, but as soon as I create another child window
both of the open child windows don't ever call it. They do both go
into the onbeforeunload appClose() function, but do not call the
window.opener.CloseChild() function inside of this routine.

Anyone have any ideas why when I have two child windows open I can't
access the window.opener functions?

I have tried taking each new window out of the array and used the
following code in CloseChild() :

CloseChild()
{

//win and totalNumWindowsCreated are both global

totalNumWindowsCreated = totalNumWindowsCreated + 1;
var win = window.open(link, "child" +
totalNumWindowsCreated,"dependent");

..
..
..
}