zIndex for Images

We have the following structure:

HomeWindow.prototype.addHeader = function() {
    this.header_banner = Ti.UI.createLabel({
        top : the_screen.getBannerTop(),
        left : the_screen.getBannerLeft(),
        width : the_screen.getBannerWidth(),
        height : the_screen.getBannerHeight(),
        backgroundImage : dir_path.R + "images/ipad/home/ipad-home-main-banner-towns-list.png",
        zIndex : 14
    });
 
    this.header_banner_shadow = Ti.UI.createLabel({
        backgroundImage : dir_path.R + "images/ipad/ui/ipad-nav-side-shadow.png",
        left : the_screen.getHorizontalShadowLeft(),
        width : the_screen.getHorizontalShadowWidth(),
        top : the_screen.getHorizontalShadowTop(),
        height : the_screen.getHorizontalShadowHeight(),
        zIndex : 14
    });
 
    this.left_banner = Ti.UI.createLabel({
        top : the_screen.getLeftBannerTop(),
        left : the_screen.getLeftBannerLeft(),
        width : the_screen.getLeftBannerWidth(),
        height : the_screen.getLeftBannerHeight(),
        backgroundImage : dir_path.R + "images/ipad/home/ipad-nav-blue-background.png",
        // backgroundColor: 'red',
        zIndex : 11
    });
 
    this.left_banner_shadow = Ti.UI.createLabel({
        backgroundImage : dir_path.R + "images/ipad/ui/ipad-nav-side-shadow.png",
        left : the_screen.getVerticalShadowLeft(),
        width : the_screen.getVerticalShadowWidth(),
        top : the_screen.getVerticalShadowTop(),
        height : the_screen.getVerticalShadowHeight(),
        zIndex : 11
    });
 
    this.right_banner = Ti.UI.createLabel({
        top : the_screen.getRightBannerTop(),
        left : the_screen.getRightBannerLeft(),
        width : the_screen.getRightBannerWidth(),
        height : the_screen.getRightBannerHeight(),
        backgroundImage : dir_path.R + "images/ipad/home/ipad-home-map.jpg",
        zIndex : 3
    });
};

Now we add buttons to the left pane:

HomeWindow.prototype.addButton = function(txt, left_pos, top_pos, img_width, img_height, img) {
    var btn = Ti.UI.createButton({
        // title : txt,
        top : top_pos,
        left : left_pos,
        height : img_height,
        width : img_width,
        backgroundImage : img,
        zIndex : 11
    });
    this.buttons[this.button_count] = btn;
    this.button_count += 1;
    // this.win.add(btn);
    return btn;
};

Now When an event fires we do this:

Ti.App.addEventListener('loadHomeContent', function(e) {
    // alert("called");
    clearPanes(function() {
        // alert("called");
        if ( typeof (e.load_slide) == "undefined") {
            if (town_detail_state) {
                central.removeSlide();
                central.openSlide(home_obj, central.getSystemObject("town"), 'town');
                central.leftSlide();
                town_detail_state = null;
            } else {
                // alert("AA");
                // central.raiseSlideWindow();
                central.leftSlide();
            }
        } else {
            central.removeScreen(home_obj);
            central.removeSlide();
        }
        central.clearScreen();
        central.addContentView(home_obj.getWindow(), e.content, e.theme);
        central.lowestWindow();
        central.displayScreen(home_obj);
        if (e.theme != "") central.addTrailMap(e.theme,home_obj);
        else central.removeTrailMap(home_obj);
    });
});

So the addTrailMap uses Zindex : 11 But is always over the top of the header, which has a higher zIndex?

Can anyone help me out with this?