Loading local images from AIR app on iOS?

This puzzles me. When I export my AIR 2.6 app to iOS, I can easily add XML files to the .ipa file and load them into my SWF by referring to them in my actionscript as if they were in the same folder as the swf file.

But with my image files, this doesn’t seem to work. Doing a traditional

var imageLoader = new Loader();
imageLoader.load(new URLRequest(url));
imageLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, imageLoaded);
function imageLoaded(e:Event):void {

results in the images not showing up when I bundle them with the swf and running them on my iPad. Why does this work for XML files but not image files?