Afrundede hjørner

Hvorfor virker mine runde hjørner ikke i Google Chrome, Opera & IE8?
http://www.racingcar.dk/eksperten/pics/rundehjoerner.JPG
http://www.racingcar.dk/eksperten/pics/rundehjoerner2.JPG
De virker fint i FF & IE7

<table width="100%" cellspacing="0" cellpadding="0">
<tr><td class="menutopleft" width="6px"><img src="Themes/HD09/images/menu-upper-left.gif" /></td>
<td class="menuuppersmall"></td>
<td class="menutopright" width="6px"></td></tr>
<tr><td class="menu" colspan="3">

  <table>
  <tr><td>Browser: </td>
  <td>Firefox 3 & IE7</td>
  </tr>
  </table>
</td></tr>
<tr><td class="menubuttomleft" width="6px"> </td>
<td width="99%" class="menulowersmall"> </td>
<td class="menubuttomright"> </td></tr>
</table>



/* Tables should show empty cells. */
table
{
    empty-cells: show;
}

/* By default (td, body..) use verdana in black. */
body, td, th , tr
{
    color: #949494;
    font-size: small;
    font-family: verdana, sans-serif;
}

/* The main body of the entire forum. */
body
{
    background-color: #151515;
    margin: 0px;
    padding: 12px 30px 4px 30px;
}

.menuuppersmall {
    background-image: url(images/menu-top.jpg);
    background-repeat: repeat-x;
    height: 6px;
    font-size: 1%;
}

.menulowersmall {
    background-image: url(images/menu-buttom.jpg);
    background-repeat: repeat-x;
    height: 6px;
    font-size: 1%;
}

.menuleft {
    background-image: url(images/menu-left.jpg);
    background-repeat: repeat-y;
    width: 6px;
    font-size: 1%;
}

.menuright {
    background-image: url(images/menu-right.jpg);
    background-repeat: repeat-y;
    width: 6px;
    font-size: 1%;
}

.menu {
    background-image: url(images/menu.gif);
    background-repeat: repeat;
}

.menutopleft {
    background-image: url(images/menu-upper-left.gif);
    background-repeat: no-repeat;
    width:6px;
    height: 6px;
    font-size: 1%;
}

.menutopright {
    background-image: url(images/menu-upper-right.gif);
    background-repeat: no-repeat;
    width:6px;
    height: 6px;
    font-size: 1%;
}

.menubuttomleft {
    background-image: url(images/menu-lower-left.gif);
    background-repeat: no-repeat;
    width:6px;
    height: 6px;
    font-size: 1%;
}

.menubuttomright {
    background-image: url(images/menu-lower-right.gif);
    background-repeat: no-repeat;
    width:6px;
    height: 6px;
    font-size: 1%;
}


Er der nogen der kan hjælpe? Det er så snart jeg sætter den inderste table ind det går galt.