title: TypeError: aLayout[(i + k)] is undefined datatables
body: <p>I am getting <code>TypeError: aLayout[(i + k)] is undefined</code> 
  in console when specifying any <code>rowspan</code> or <code>columnspan</code> value. It is working fine without this, but I need to have these things as I need to group certain columns. I am using zero config datatables and code is given below.</p>
  
  <pre><code>jQuery(document).ready(function($) {
      $("#points_table").DataTable();
  });
  </code></pre>
  
  <p>and the error is showing on this line in datatable JS :</p>
  
  <p>TypeError: aLayout[(i + k)] is undefined</p>
  
  <p>"unique": bUnique</p>
  
  <p>My datatable version is <code>1.9.4</code></p>
  
  <p>Thanks in advance</p>