Let's try to be a little friendlier with new dom elements.

diabox.js

observe_anchors : function(){
  box = this;
  $(document.body).addEvent('click:relay(a[rel*="box"])', function(e){
    var a = e.target;
    if(a.rel && a.rel.test(box.opt.rel_target)){
      box.set_loading();
      box.construct_renderable_from_link(a).render();
      e.stop();
    }
  });
},

Just replace the observe_anchors method with the one provided here.