title: Paired Stacked Multibar
body: <p>Starting form the example on <strong><a href="http://nvd3.org/examples/multiBar.html" rel="nofollow noreferrer">Grouped / Stacked Multi-Bar</a></strong> I draw this graph using nvd3.js:
  <img src="https://i.stack.imgur.com/9pHek.png" alt="Grouped bars"></p>
  
  <p>When I click on the Stacked control, the second series is not drawn from the start of the axis:
  <img src="https://i.stack.imgur.com/KA55R.png" alt="Stacked bars"></p>
  
  <p>I dont understand why is that. Here is a jsfiddle example of my code: <a href="http://jsfiddle.net/58rw7/1/" rel="nofollow noreferrer">http://jsfiddle.net/58rw7/1/</a></p>
  
  <p>My data looks like this:</p>
  
  <pre><code>[
      {
          "key": "a - BAR_FM - kWh - F1",
          "values": [
              {
                  "x": "0_0",
                  "y": 50,
                  "label": "1/1/2014"
              },
              {
                  "x": "0_1",
                  "y": 108,
                  "label": "2/1/2014"
              },
              {
                  "x": "0_2",
                  "y": 109,
                  "label": "3/1/2014"
              }
          ]
      },
      {
          "key": "a - CONDIZIONAMENTO_IDRICO - kWh - F1",
          "values": [
              {
                  "x": "1_0",
                  "y": 186,
                  "label": "1/1/2014"
              },
              {
                  "x": "1_1",
                  "y": 186,
                  "label": "2/1/2014"
              },
              {
                  "x": "1_2",
                  "y": 184,
                  "label": "3/1/2014"
              }
          ]
      }
  ]
  </code></pre>
  
  <p>Why the second series is not drawn from the start of the axis? How can I do that?</p>