strange error with droppables

strange error with droppables

I'm currently trying to implement a drag/droppable selection system, but I'm getting a bug that I can't seem to crush. I have 2 ul lists sitting above and below each other, the first (.snapTo1) with empty li's, the second (draggable1) with the content to be dropped into snapTo to make a full product.

When I drag a draggable li onto the corresponding place in snapTo, it acts as if it is going to snap, and when I drop it, a class is added to snapTo, but the draggable disappears.

I can fix it, however, to do this, I've had to break the JS (after adding class, I add the nonsense code .break(forsnap); and this makes the draggable stay in place. This however, isn't the proper way of doing things, and if I need to add any additional events later down the line I imagine this will be quite susceptible to breakage.

My code is below, if anyone has had a similar issue, or can point me in the right direction that would be great.

Thanks, Dan
  1.         $("#draggable1 li").draggable({
                helper: 'clone',
                snap: '.snapTo1',
                snapMode: 'inner'
            });
           
            $(".snapTo1").droppable({
                accept: '#draggable1 li',
                drop: function(event, ui) {
                    $(this).addClass('').break(forsnap);
                }
            });