This page tests whether or not comment nodes disrupt the row index of rows in a table.

Row One
Row Three
PASS: document.getElementById('tr1').parentNode.childNodes.length == 5 should be true and is.
PASS: document.getElementById('tr1').rowIndex == 0 should be true and is.
PASS: document.getElementById('tr2').rowIndex == 1 should be true and is.
PASS: document.getElementById('tr3').rowIndex == 1 should be true and is.