DropDown IE 7 aterrorizando

Bom dia, galera infelizmente estou aqui de novo com um problema, um menu dropdown, funciona muito bem no FF, Chrome, IE8, IE9,

mas ai tem o fd... do IE6 e IE7, o problema é quando o menu rola para baixo, nos outros browsers ele rola na boa, e fica por cima do conteudo, agora no IE6 e IE7, ele rola, mas fica por baixo do conteudo, ja pesquizei bastante na net, vi varios tópicos em varios foruns, já tentei mudar a position algumas vzs, já tentei usar "*z-index", e nada, preciso de uma luz, alguem poderia me ajudar ?

Segue abaixo o codigo do menu em html e css, acredito q oq está em jquery não precisaria ser mostrado, segue abaixo os outros:

HTML

 <div id="myslidemenu" class="jqueryslidemenu">

 <ul class='menu_topo'>

 <li id='li_about'>
 <a href='#' class='about'>About</a>

 <ul class='submenubg_about'>

 <li><a href='#'>Sobre Nós</a></li>

 </ul>
 </li>

 <li id='li_informacoes'>
 <a href='#' class='informacoes'>Informações</a>

 <ul class='submenubg_info'>
 <li><a href='#'>Quem Somos</a></li>
 <li><a href='#'>Nossa Revista</a></li>
 <li><a href='#'>Publicidade</a></li>
 <li><a href='#'>Trabalhe Conosco</a></li>
 <li><a href='#'>Contato</a></li>
 </ul>

 </li>

 <li id='li_servicos'>
 <a href='#' class='servicos'>Serviços</a>
 <ul class='submenubg_serv'>

 <li><a href='#'>Classificados</a></li>
 <li><a href='#'>Promoções</a></li>
 <li><a href='#'>Informações</a></li>

 <li><a href='#'>Mapas</a></li>
 <li><a href='#'>Cameras Online</a></li>
 <li><a href='#'>Telefones Úteis</a></li>

 </ul>
 </li>

 <li id='li_canais'>
 <a href='#' name='canais' class='canais'>Canais</a>

 <ul class='submenubg_canais'>

 <li><a href='#'>Bairros</a></li>
 <li><a href='noticias.php'>Notícias</a></li>
 <li><a href='#'>Noite na Barra</a></li>
 <li><a href='#'>Lazer e Cultura</a></li>
 <li><a href='#'>Guia Bairro</a></li>

 <li><a href='#'>Artigos</a></li>
 <li><a href='#'>Entrevistas</a></li>
 <li><a href='colunas.php'>Colunas</a></li>
 <li><a href='#'>Fotos e Eventos</a></li>
 <li><a href='#'>Copa do Mundo</a></li>
 <li><a href='#'>Olímpiadas</a></li>

 <li><a href='#'>Fondue</a></li>

 </ul>
 </li>

 </ul>

 </div>
 <!-- FIM DO MENU DD NO TOPO ############################### -->

CSS

@charset "utf-8";
/ CSS Document /

.jqueryslidemenu {
width:100%;
*z-index:99;
}

.jqueryslidemenu ul {

list-style-type:none;
*z-index:98;
display:block;
margin:0;
padding:0;
}

/Top level list items/
.jqueryslidemenu ul li {

position:relative;
float:right;
display:inline;
*z-index:97;
}

/Top level menu link items style/
.jqueryslidemenu ul li a {

display:block;
color:#09C;
text-decoration:none;
*z-index:96;
padding:4px 10px 15px;
}

* html .jqueryslidemenu ul li a {

display:inline-block;
*z-index:95;
}

.jqueryslidemenu ul li a:link,.jqueryslidemenu ul li a:visited {

color:#FFF;
}

.jqueryslidemenu ul li a.canais:hover, .jqueryslidemenu ul li#li_canais:hover {

color:#FFF;
background-image:url(../images/menu/teste_menu_img.png);
background-repeat:no-repeat;
background-position:5px 0;
*z-index:94;
}

.jqueryslidemenu ul li a.servicos:hover, .jqueryslidemenu ul li#li_servicos:hover {

color:#FFF;
background-image:url(../images/menu/teste_menu_maior.png);
background-repeat:no-repeat;
background-position:3px 0;
*z-index:93;
}

.jqueryslidemenu ul li a.informacoes:hover, .jqueryslidemenu ul li#li_informacoes:hover {

color:#FFF;
background-image:url(../images/menu/teste_menu_info.png);
background-repeat:no-repeat;
background-position:1px 0;
}

.jqueryslidemenu ul li a.about:hover, .jqueryslidemenu ul li#li_about:hover {

color:#FFF;
background-image:url(../images/menu/teste_menu_about.png);
background-repeat:no-repeat;
background-position:5px 0;
}

/1st sub level menu/
.jqueryslidemenu ul li ul {

position:absolute;
left:0;
display:block;
visibility:hidden;
z-index:1;
}

/Sub level menu list items (undo style from Top level List Items)/
.jqueryslidemenu ul li ul li {

display:list-item;
background-color:#500;
float:none;
z-index:1;
}

/All subsequent sub menu levels vertical offset after 1st level sub menu /
.jqueryslidemenu ul li ul li ul {

top:0;
}

/ Sub level menu links style /
.jqueryslidemenu ul li ul li a {

width:180px;
font-size:14px;
line-height:22px;
border-top-width:0;
border-bottom:1px solid #500;
text-align:left;
background-color:#600;
background-image:none;
margin:0;
padding:0 0 0 5px;
}

.jqueryslidemenu ul li ul.submenubg_canais li a:hover,.jqueryslidemenu ul li ul.submenubg_info li a:hover,.jqueryslidemenu ul li ul.submenubg_serv li a:hover {

background-color:#500;
background-image:none;
}

.submenubg_info,.submenubg_canais,.submenubg_serv {

background-image:none;
background-color:#600;
color:#500;
}