Why doesn't innerHTML work in IE?
It can be a lot of different issues. Older versions of IE don't implement the property properly or even at all in some really old versions. One thing I found was that if you give two different elements the same name and id properties, it will confuse IE. For instance:
<td name="td1" id="test">1</td>
<td name="td2" id="id1">2</td>
The above will confuse IE and won't work when you use document.getElementByID().