Got it! Thanks! John
When trying to access "this" inside my onDragEnd callback, the FireFox 28.0 debugger is showing "this" as an instance of "Window" instead of an instance of "Draggable" as stated in the Draggable docs. Here's my simple codepen: http://codepen.io/anon/pen/dKEki ... and the FireFox debugger display at a breakpoint inside the callback.