div pushing table height in firefox

[wac]

I've got a single row table with DIVs in the Cells surrounding content.
The divs are overflow:auto, so that I expect the DIVs to be sized to the cells
they are in and whenever the content grows over that size, scroll bars appear. This works fine in IE, but in firefox, whn the content gets large, the div simply pushes the table larger instead of making scroll bar. Any ideas???


<table cellpadding="0" cellspacing='0' border='1' style='height:40%'>
<tr>
<td>
<div style='overflow:auto;height:100%;border:solid yellow 2px'>
some content
</div>
</td>
<td>&nbsp;</td>
<td>
<div style='overflow:auto;height:100%;border:solid yellow 2px'>
some content
</div>
</td>
</tr>
</table>

[_Aerospace_Eng_]

Firefox has this bug about making a div overflow:auto; while the height is 100%. The only work around I've found is to use an iframe or to use some JS to set the height of the div dynamically.