Actionscript conflict with listbox and popup window

I’ve got a listbox as a componant with the following action on the first frame of the movie:

function foo(myVar) {
gotoAndPlay(myVar.getSelectedItem().label);
}

In addition I have a pop up window following the directions from:
http://www.kirupa.com/developer/mx/centered_popup.htm

The problem is once I open the pop up window, my listbox won’t function correctly again. No matter what I choose, it goes back to the frame where the pop up button was.
In addition, I get an error when I try to reopen the pop up window after I close it.

Any help with the actionscript would be appreciated.
Thanks
Steve