Erro no IE

Eis o codigo ... no FireFox ta tudo okay mais no IE nao muda a cor da celula quando coloca o mouse

<style type="text/css">
#tabela {background-color:#99CC99}
#tabela:hover {background-color:#CCFF33}

</style>

<table width="250" border="1" cellspacing="0" cellpadding="0">
 <tr>
	<td id="tabela"> </td>
	<td> </td>
 </tr>
 <tr>
	<td> </td>
	<td id="tabela"> </td>
 </tr>
 <tr>
	<td id="tabela"> </td>
	<td> </td>
 </tr>
 <tr>
	<td> </td>
	<td id="tabela"> </td>
 </tr>
</table>