Given that you are using unique images for each menu item, can you not just round the corner of the image that appears last in the menu? I think I'm missing something.
Maybe the answer could be to add a class of 'last' to that menu item's anchor and apply the corner image to the top right of that, as it would appear on top of the li image. Or maybe I'm not visualising what you intend to do properly. Joel Birch.
