IE not removing required child roles for a table role=presentation

Hi all,

looking at this code example in an object inspection tool:

<table role="presentation">
<tr>
  <td>
  1
  </td>
  <td>2</td>
</tr>
</table>


It is my understanding (from the spec and UIAG) that the required child
elements (td's and tr's) should inherit the role=presentation from the
table element.
This occurs in Firefox (for example) but does not occur in IE 9. In IE the
td elements are still represented as table cells in the accessibility tree.

for the following IE does remve the required child roles for li's:

<ol role="presentation">
    <li>1
    <li>2
    <li>3
</ol>

is the exposing of td roles a known bug or am I reading/ doing something
wrong?

-- 
with regards

Steve Faulkner