.sliderwrapper {
  position: relative; /*leave as is*/
  overflow: hidden; /*leave as is*/
}

.sliderwrapper .contentdiv {
  visibility: hidden; /*leave as is*/
  position: absolute; /*leave as is*/
  left: 0;  /*leave as is*/
  top: 0;  /*leave as is*/
  overflow:hidden;
  color: white;
  width: 720px; /*width of content DIVs within slider. Total width should equal slider's inner width (390+5+5=400) */
  height: 210px;
  filter:progid:DXImageTransform.Microsoft.alpha(opacity=100);
  -moz-opacity: 1;
  opacity: 1;
}