JQuery drag and drop callback called after sorting from sortable

I have a list of drag and drop objects associated with a sort list. The drag and drop function works great, as does the sort. The thing is, before sorting the list, I need to create a record in the DB (using rails). So I use $ .post, which works great, but I need to change the id of the inserted item. I do this by changing the id of the inserted item using the $ .post callback. Works fine, but it happens AFTER sorting. And if you're wondering why I didn't use the draggable stop callback because it does the same thing. Here's the shorthand code (remove unnecessary db stuff):

    $("#operations_container").sortable({items:'.process_small', axis:'y', update: function(ev,ui) {
    if (ui.item.attr('id').match("workcenter"))
    {
        $.post('/operations', 'fancyrailspoststuffignore', function(data) {
                    $("#operations_container > #workcenter_" + workcenterid).attr("id", "operation_" + data.operation.id);
                    }, "json");
    }   
    $.post('/jobs/sort/<%= @job.id %>', 'morefancyschamncyrailsjunk);
}});

      

        
        
        
      

    

The sorted container is simple:

<div id="operations_container" class="in_grid">
</div>

      

        
        
        
      

    

So, it seems to me that all calls are called after sorting. It's true? How do you get around this if you need to update the DOM before sorting?

UPDATE: In case they are missing in the comments, here are sample images and examples to illustrate the issue.

Image: http://dl.getdropbox.com/u/1826667/sortable.png Sample files: http://dl.getdropbox.com/u/1826667/jquery_callback_order.zip

So it seems that callbacks always end at the end of any other events no matter where they are called (@ .post callback before the update being sorted is still called last, etc.). I don't think this is a bug in JQuery (although I find it strange); I am trying to make multiple posts (which are required as they depend on each other, create a record and then sort) in a single move, which may not be the way to do it. I will try to work around this in the backend (something almost works for me) so I will consider it private. Thanks to everyone who helped with the problem. SO rules.

MEGAIMPORTANTUPDATE: it works! Sean got this (see answer) and I'm still a little dizzy. It's been a few days on this one. Thanks again to everyone, and especially Sean. You rock.