gistfile1.css

/** IE-specific **/
.ie8, .ie7, .ie6 {
  .primary-nav {
    float: left;

    ul.menu li {
      background-image: url(../images/ie/nav_bg.png);
      background-position: 50%;

      :hover {
        background-image: url(../images/ie/nav_bg_active.png);
      }
      li {
        background-image: none;
        :hover {
          background-image: none;
        }
      }
    }
  }