sidebar_heading lässt sich nicht unsichtbar machen

<style type="text/css">
<!--
td.nav{background-image: url(http://img.webme.com/pic/d/dagangclan/leer1.jpg);}
td.nav:hover{background-image: url(http://img.webme.com/pic/d/dagangclan/arrow5.gif);}
td.edit_below_nav{visibility: hidden;width: 0px;}
td.edit_navi_headbg{background-image: url(http://img.webme.com/pic/d/dagangclan/t6.jpg);}
td.nav_heading{background-image: url(http://img.webme.com/pic/d/dagangclan/k1.jpg);}
td.edit_content_top{visibility: hidden;width: 0px;}
td.edit_content_bottom2{visibility: hidden;width: 0px;}
body  {background-image: url(url);background-color: #ffffff;}
td.edit_rechts_cbg{background-image: url(URL);}
td.edit_rechts_sbg{visibility: hidden; width: 0px ;}
td.edit_content_bottom2{visibility: hidden;width: 0px;}
td.edit_content{background-image: url(url);width: 0px;}
td.edit_rechts_bottom{background-image: url(url);}
td shouty {background-image: url(url);background-color: #ffffff;}
td.edit_content_bottom{background-image: url(url);width: 0px;}
td.edit_rb_footer{visibility: hidden;}   

td edit_sidebar_heading{visibility: hidden;}

-->
</style>