I recently ran into a problem, i've created a tabgroup with 3 tabs in it, now i want to change the background image of the entire tabgroup, so it looks like this:

I've tried it like this:

var tabGroup = Ti.UI.createTabGroup({
    backgroundImage: 'assets/tabGroupBg.png'
});

and on the tab itself

var startupTab = Ti.UI.createTab({
    icon: 'assets/icons/KS_nav_views.png',
    title: 'Test',
    backgroundImage: 'assets/tabGroupBg.png',
    window: startupWindow
});

But it's not working in anyway, is there something else you have to do?