title: jQuery $.ajax() call to get JSON from Rails 3 controller results in 304 Not Modified?
body: <p>In application.js I have:</p>
  
  <pre><code>$("#combo_box").live('change', (function() {
      $.ajax( {
                      url: '/my_controller/get_data',
                      data: {id: some_id},
                      success:  function(data){ do_stuff_with_data(data) }
               }
             )
      } ) )
  </code></pre>
  
  <p>and in my_controller code I have:</p>
  
  <pre><code>  def get_data
      id = params[:id]
  
      @data = MyModel.DoSomeStuff(id)
  
      respond_to do |format|
        format.js { render :json =&gt; @data}
      end
    end
  </code></pre>
  
  <p>But for some reason the function in <code>success</code> is only run once (I think) and the rest of the times Firebug reports a <code>304 Not Modified</code> when the combo box change triggers an ajax call.</p>
  
  <p>How does that work? Thanks!</p>