Problemas con un menú desplegable en pc

[fmanzuet]

.menu {
font-family: Geneva, Arial, Helvetica, sans-serif;
width:936px;
height:42px;
position:relative;
font-size:11px;
margin: 0;
z-index: 1;
}
.menu ul li a {
display:block;
text-decoration:none;
color:#fff;
font-weight:bold;
width:100px;
height:42px;
text-align:center;
border-bottom: 0;
background-image:url(images/preguntas_frecuentes.jpg);
line-height:48px;
font-size:11px;
overflow:hidden;
padding-left: 1px;
}

/* first and last tabs */
.menu .one {
background-image:url(images/preguntas_frecuentes.jpg);
padding-left: 1px;
margin-right: -1px;
}
.menu .three {
background-image:url(images/preguntas_frecuentes.jpg);
}

.menu ul {padding:0; margin:0; list-style: none;}
.menu ul li {float:left; position:relative;}
.menu ul li ul {display: none;}

/* button hover properties */
.menu ul li:hover a {
color:#536780;
background-image: url(/images/boton_amarillo.jpg);
}
.menu ul li:hover ul {
display:block;
position:absolute;
top:42px;
left:0;
width:160px;
margin: 0;
padding: 0;
}
.menu ul li:hover ul li a.two {background:#6a3; color:#fff;}
.menu ul li:hover ul li:hover a.two {background:#6fc; color:#544a3a;}
.menu ul li:hover ul li ul {display: none;}

.menu ul li:hover .one {
color:#000000;
background-image: url(/images/boton_amarillo.jpg);
}
.menu ul li:hover .three {
color:#000000;
background-image: url(/images/boton_amarillo.jpg);
}

/* dropdown properties */
.menu ul li:hover ul li a {
background-image: none;
display:block;
height: 28px;
line-height: 26px;
color:#043454;
width:120px;
text-align:left;
margin: 0;
padding:0 0 0 11px;
font-weight:normal;
}
.menu ul li:hover ul {
margin: 0 0 0 3px;
padding: 0;
background-image: url(images/fondoverde.jpg);
background-repeat:no-repeat;
background-position:bottom left;
}
.menu ul li:hover ul .hlight {
background-image: url(images/fondoverde.jpg);
margin-right: 1px;
}

/* dropdown selected properties */
.menu ul li:hover ul li a:hover {color:#fff; background-image: url(../img/nav/hlight.png);}

.menu ul li:hover ul li:hover ul {display:block; position:absolute; left:105px; top:0;}
.menu ul li:hover ul li:hover ul.left {left:-105px;}