The below code creates a NavigationGroup with the first window containing a custom 'back' button to close itself and another button to open a second window. The second window has a custom 'back' button to close itself.

The custom 'back' buttons don't work in 1.3. I applied this patch to get them to work:
925-cant-close-window-in-nav-group

The issue

1 Click on the 'back' button in the second window.

2 The second window closes.

3 The first window is shown.

4 The second window's 'back' button shows on the first window.

In step 4 I would expect the first window's back button to show on the first window.

If I remove the first window's 'back' button and run through steps 1 through 3, when the first window is shown it has no 'back' button as expected.

I also tried setting the left nav buttons in an 'open' listener for each window but this didn't help either.

Bug, no?

  // window 1 setup
  var win1 = Titanium.UI.createWindow({
      backgroundColor:"red",
      title:"Window 1"
  });

  var openWin2Button = Titanium.UI.createButton({
    title: 'open win 2',
    height:40,
    width:200
  });

  openWin2Button.addEventListener( 'click', function() {
    nav.open(win2);
  });

  win1.add(openWin2Button);

  var closeWin1Button = Titanium.UI.createButton({
    title: 'Close me'
  });
  closeWin1Button.addEventListener( 'click', function() {
    nav.close(win1);
  })
  win1.setLeftNavButton(closeWin1Button);


  // window 2 setup
  var win2 = Titanium.UI.createWindow({
    backgroundColor: "#0f0",
    title: "Window 2"
  });

  var closeWin2Bbutton = Titanium.UI.createButton({
    title: 'close win2'
  });

  closeWin2Bbutton.addEventListener( 'click', function() {
    nav.close(win2);
  });

  win2.setLeftNavButton(closeWin2Bbutton);


  // nav group setup
  var nav = Titanium.UI.iPhone.createNavigationGroup({
     window : win1
  });

  var win = Titanium.UI.createWindow();
  win.add(nav);
  win.open();