1em height row in IE (spanned row)

[W@cek]

How to set height: 1em row in IE in this example?
(firefox and opera set it to 1em but IE not)

|---------------|
| IMG |hei.1em |
| hei. |---------
| 100px| |
-----------------

_my code:_
<table border="0" cellpadding="0" cellspacing="0">
<tr>
<td rowspan="2" style="width: 100px;">
<img src="obrazek.jpg" alt="" style="border: none;width: 100px" />
</td>
<td colspan="2" style="background-color: #ddd;height: 1em">text header
</td>
</tr>
<tr>
<td colspan="2" valign="top" >
other text .....
</td>
</tr>
</table>