Problema com borda no :hover

Quando há o :hover o texto se movimenta, pq?

 <style type="text/css">
 #scrollTest {
 width: 400px;
 height: 285px;
 overflow: auto;
 background-color: #000;
 border: 1px solid #D6D6D6;
 color: #333;
 }

 .container
 {
 height: 32px;
 line-height: 32px;
 _font-family: Tahoma, Sans-Serif;
 font-family: Courier New, Monospace;
 font-size: 11px;
 }

 #scrollTest .container:hover
 {
 border: 1px solid #CCC;
 }
	</style>

<div id="scrollTest">

 <table>
 <tr>
 <td class="container">
 Rafael Fernandes D Orazio
 </td>
 </tr>
 <tr>
 <td class="container">
 Meire Fernandes D Orazio
 </td>
 </tr>
 <tr>
 <td class="container">
 Eliana Fernandes Malfarage
 </td>
 </tr>
 </table>

</div>