Css overlay element not invisible

Question

See: http://schhh.dk/frivilligraadet/

The box with videos at the bottom are, in ie8, displayed as:

I actually tried to make a jsfiddle, but here there is no problem: http://jsfiddle.net/q5T8Y/7/

.view-youtube-videoer .views-field-field-video .ytb-play {
  position: absolute;
  display: block;
  width: 230px;
  height: 128px;
  background: transparent url('http://schhh.dk/frivilligraadet/sites/all/themes/frivilligraadet/images/play.png') no-repeat 50% 50%;
  opacity: 0.7;
  filter:alpha(opacity=70);
}

Answer 1

It's because you need to set "width" and "display: block" for span.ytb-video In your case width should be 230px

http://screencast.com/t/U2QPWvszGN