title: dompdf table rendering issue
body: <p>I'm using DomPDF to generate invoices in a project I'm working on.
  I've done so several times before and never had any trouble but since today however It got so slow that the maximum execution time gets reached.
  I've confirmed that this happens because of: <code>$dompdf-&gt;render()</code>
  I'm generating some tables to display the data in. but is seems to find this table quite difficult. Does anyone know what could be the problem?</p>
  
  <p>dompdf and my table can be found: <a href="http://pastebin.com/G585VQma" rel="nofollow">http://pastebin.com/G585VQma</a>
  (figured I'd put it on pastebin to save some space)</p>