title: jqGrid id undefined, why?
body: <p>I have this code:</p>
  
  <pre><code>$(grid).jqGrid('addRowData', 'foo', d);
  $(grid).jqGrid('addRowData', 'bar', 'baz');
  </code></pre>
  
  <p>As viewed in FireBug, it creates this DOM:</p>
  
  <pre><code>&lt;tr id="undefined" class="ui-widget-content jqgrow ui-row-ltr" tabindex="-1" role="row"&gt;
  &lt;tr id="bar" class="ui-widget-content jqgrow ui-row-ltr" tabindex="-1" role="row"&gt;
  </code></pre>
  
  <p>The data expressed in 'd' matches the column model and it displays correctly (so I know the grid basically works fine). BUT, the 'id' on the first row is not set. On the other hand, 'baz' is garbage; this creates a blank row, BUT, the 'id' is correctly set to 'bar'.</p>
  
  <p>In both cases I am sure the ID's are unique within my DOM, plus, I have observed that using non-unique ID's does not cause any immediate problems.</p>
  
  <p>SO; I can't see why the id on the first row is not set. Any ideas?</p>