div.vud-comment-dimmed {
  filter:alpha(opacity=50);
  -ms-filter:"alpha(opacity=50)";
  -moz-opacity:0.5;
  -khtml-opacity: 0.5;
  opacity: 0.5;
}

div.vud-comment-dimmed:hover {
  filter:alpha(opacity=100);
  -ms-filter:"alpha(opacity=100)";
  -moz-opacity: 1;
  -khtml-opacity: 1;
  opacity: 1;
}