Muchas gracias mikmoro; el código es el siguiente:
En el PHP
<ul id="navmenu-h">
<li><a href="#" class="nav-particulars"><img src="media/shim.gif" width="88" height="32"></a>
<ul>
<li class="primer"><a href="#">OPCION 1</a></li>
<li><a href="#">OPCION 2</a></li>
<li><a href="#">OPCION 3</a></li>
<li><a href="#">OPCION 4</a></li>
</ul>
</li>
<li><a href="#" class="nav-corporatiu"><img src="media/shim.gif" width="88" height="32"></a></li>
<li><a href="#" class="nav-quisom"><img src="media/shim.gif" width="88" height="32"></a>
<ul>
<li class="primer"><a href="#">OPCION 1</a></li>
<li><a href="#">OPCION 2</a></li>
<li><a href="#">OPCION 3</a></li>
</ul>
</li>
<li><a href="#" class="nav-faqs"><img src="media/shim.gif" width="88" height="32"></a></li>
<li><a href="#p" class="nav-reservat"><img src="media/shim.gif" width="88" height="32"></a></li>
</ul>
</div><!-- fi ulmenus -->
[/PHP]
Y EN EL CSS:
/* desplegable ------------------------------------------------------------------------------ */
ul#navmenu-h img {
border:0;
}
ul#navmenu-h {
margin: 0;
border: 0 none;
padding: 0 auto 0 auto;
/*padding-left:60;*/
width: 550px; /*For KHTML*/
list-style: none;
height: 30px;
font: normal 0.9em/1.5em BentonSansCond-Bold, Geneva, Arial, Helvetica, Verdana, sans-serif;
}
ul#navmenu-h li {
margin: 0;
border: 0 none;
padding: 0;
float: left; /*For Gecko*/
display: inline;
list-style: none;
position: relative;
width:88px;
height: 32px;
color:#e9e9e8;
}
ul#navmenu-h li a.nav-quisom {
overflow:hidden;
background:url(media/_quisom.jpg) no-repeat;
}
ul#navmenu-h li a.nav-quisom:hover, ul#navmenu-h li a.nav-faqs:hover, ul#navmenu-h li a.nav-particulars:hover, ul#navmenu-h li a.nav-corporatiu:hover, ul#navmenu-h li a.nav-reservat:hover {
background-position: 0px -32px;
}
ul#navmenu-h li a.nav-faqs {
overflow:hidden;
background:url(media/_faqs.jpg) no-repeat;
}
ul#navmenu-h li a.nav-particulars {
overflow:hidden;
background:url(media/_particulars.jpg) no-repeat;
}
ul#navmenu-h li a.nav-corporatiu {
overflow:hidden;
background:url(media/_corporatiu.jpg) no-repeat;
}
ul#navmenu-h li a.nav-reservat {
overflow:hidden;
background:url(media/_a_reserv.jpg) no-repeat;
}
ul#navmenu-h ul {
margin: 0;
border: 0 none;
padding: 0;
width: 150px;
list-style: none;
display: none;
position: absolute;
top: 25px;
left: 0;
}
ul#navmenu-h ul:after /*From IE 7 lack of compliance*/{
clear: both;
display: block;
font: 1px/0px serif;
content: ".";
height: 0;
visibility: hidden;
}
ul#navmenu-h ul li {
width: 150px;
float: left; /*For IE 7 lack of compliance*/
display: block !important;
display: inline; /*For IE*/
line-height:0.7em;
background-color:#ababab;
padding-left:1em;
padding-right:1.5em;
padding-top:1.4em;
border-bottom:1px solid #ABABAB;
text-align:left;
background-color:#e2e2e2;
font: normal 0.9em/1.5em BentonSansCond-Book, Geneva, Arial, Helvetica, Verdana, sans-serif;
}
ul#navmenu-h ul li.primer {
margin-top:6px;
}
/* Root Menu */
ul#navmenu-h a {
border: 0 none;
padding: 0;
float: none !important; /*For Opera*/
float: left; /*For IE*/
display: block;
background: transparent;
color: #000;
font: bold 1em/1.5em BentonSansCond-Book, Arial, Helvetica, Verdana, sans-serif;
text-decoration: none;
height: auto !important;
height: 1%; /*For IE*/
font: normal 0.9em/1.5em BentonSansCond-Book, Geneva, Arial, Helvetica, Verdana, sans-serif;
}
ul#navmenu-h a.actiu {
color:#333;
}
/* Root Menu Hover Persistence */
ul#navmenu-h a:hover,
ul#navmenu-h li:hover a,
ul#navmenu-h li.iehover a {
background-position: 0px -32px;
color: #b3b3b3;
}
/* 2nd Menu */
ul#navmenu-h li:hover li a,
ul#navmenu-h li.iehover li a {
font: normal 1em/1.5em BentonSansCond-Book, Geneva, Arial, Helvetica, Verdana, sans-serif;
float: none;
color: #737373;
}
ul#navmenu-h li:hover li a.nav-quisom, ul#navmenu-h li:hover li a.nav-faqs, ul#navmenu-h li:hover li a.nav-corporatiu, ul#navmenu-h li:hover li a.nav-particulars {
}
/* 2nd Menu Hover Persistence */
ul#navmenu-h li:hover li a:hover,
ul#navmenu-h li:hover li:hover a,
ul#navmenu-h li.iehover li a:hover,
ul#navmenu-h li.iehover li.iehover a {
color: #b3b3b3;
}
ul#navmenu-h li:hover ul,
ul#navmenu-h ul li:hover ul,
ul#navmenu-h ul ul li:hover ul,
ul#navmenu-h li.iehover ul,
ul#navmenu-h ul li.iehover ul,
ul#navmenu-h ul ul li.iehover ul {
display: block;
}