Android actionBar.displayHomeAsUp causes the app to crash

I have the weirdest issue ever, Same code I'm using in multiple windows on an android app, causes the app to crash on a specific window...

win.addEventListener("open", function (evt) { 
    var actionBar = win.activity.actionBar; 
        actionBar.displayHomeAsUp = true;
 
        actionBar.backgroundImage = 'images/bg_navbar_short.png';
 
        actionBar.onHomeIconItemSelected = function () {      
            win.close();
          }; 
});

I don't know specificaly wich line from this function is causing it.. but if I isolate this code .. and get the lame window without the icon on top it works.. If I try to do an action bar.. it crashes and i get the "Unfortunately App stopped running" dialog