Strange issue with link and background in css in Internet Explorer 7

I have a file with the following css/html and for some reason the only time the link will work is if I apply a color to the background of the A tag. I am using this link as an overlay to trigger some other animations in JavaScript. This has me stumped, even the border is clickable but not inside unless background is applied.

<a id="domo-action" href="#wrapup-video" class="secret 开发者_开发技巧yum" data-yummy="9">click for domo</a>

a#domo-action {
  display: block;
  height: 180px;
  left: 0;
  position: absolute;
  text-indent: -9999px;
  top: 20px;
  width: 188px;
  z-index: 999;
  cursor: pointer;
  border: 1px solid #999;
  background: transparent;
}   

If I remember correctly, the workaround for this is to apply a transparent blank.gif as the background-image.