I am using the following css to create an overlay but it still isn't working in IE. Can anyone suggest what I might need to do to have the desired effect?

The image and overlay can be seen here

  #slider .slideoverlay{
    /* Fallback for web browsers that doesn't support RGBa */
    background: rgb(255, 255, 255);
    /* RGBa with 0.6 opacity */
    background: rgba(255, 255, 255, 0.8);
    /* For IE 5.5 - 7*/
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#ddffffff, endColorstr=#ddffffff);
    /* For IE 8*/
    -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#ddffffff, endColorstr=#ddffffff)";
    position: absolute;
    bottom: 0px; left: 0px;
    width: 825px; padding: 8px 18px 0px 12px;
    height: 72px;
    font-size: 28px; line-height: 31px;
    overflow: none;