wayfinder and 960 grid validation problem

<div class="grid_12">
				<ul class="nav main">
				<ul><li class="active"><a href="/homepage.html" title="Home page" >HOMEPAGE</a></li>
<li><a href="/treatments.html" title="Treatments" >TREATMENTS</a></li>
<li><a href="/skin_care_products.html" title="Product page" >PRODUCTS</a></li>
<li><a href="/skin_types.html" title="Skin types" >SKIN TYPES</a></li>

<li><a href="/galvanic.html" title="Galvanic" >GALVANIC SPA</a></li>
<li class="last"><a href="/ayurveda.html" title="Ayurveda" >AYURVEDA</a></li>
</ul></ul>
			</div>
				<div class="clear"></div>

/* navigation (horizontal subnavigation)
----------------------------------------------- */
ul.nav,
ul.nav * { margin:0;padding:0;}
ul.nav {
  position:relative;
  background:#666;
  max-width:100%;
  height:2.5em;
  }
ul.nav li {
	cursor:pointer;
	float:left;
	text-align:center;
	list-style-type:none;
	font-weight:normal;
}
ul.nav li ul {
	cursor:default;
	width:100%;
	max-width:100%;
	position:absolute;
	height:auto;
	top:2.5em;
	background-position:0 0 !important;
	left:-9000px;
}
ul.nav li ul li {
	padding:0;
	border:none;
	width:auto;
	max-width:none;
}
ul.nav li a {
	color:#fff;
	background:#666;
	font-weight:bold;
	text-decoration:none;
	display:block;
	float:left;
	padding:0 1em;
	height:2.4em;
	line-height:2.5em;
}
ul.nav li ul li a {
	position:relative !important; /* ie Mac */
	cursor:pointer !important;
	white-space:nowrap;
	line-height:2em;
	height:2em;
	font-weight:normal;
	color:#666;
	background-position:0 50% !important;
}

ul.nav li:hover a,
ul.nav li a:hover,
ul.nav li a:focus {color:#000; background:#ccc;}
ul.nav li a:active {color:#666; background:#fff;}
ul.nav li:hover ul {left:0;z-index:10}
ul.nav li ul,
ul.nav li {background:#ccc !important}
ul.nav li:hover ul li a {color:#444;}
ul.nav li:hover ul li a:hover {color:#000; background:#fff;}
ul.nav li:hover ul li a:active {color:#666; background:#fff;}

ul.nav li.current a {color:#666; background:#fff; cursor:default; font-weight:bold;}
ul.nav li.current ul {left:0;z-index:5}
ul.nav li.current ul,
ul.nav li.current {background:#ccc !important}
ul.nav li.current ul li a {color:#444; background:#ccc; font-weight:normal;}
ul.nav li.current ul li a:hover {color:#000; background:#fff;}
ul.nav li ul li.current a,
ul.nav li ul li.current a:hover,
ul.nav li.current:hover ul li a:active {color:#666; background:#fff;}


/* navigation (vertical subnavigation)
----------------------------------------------- */
ul.nav {
  background:#fff;
}
ul.main li {
  position:relative;
  top:0;
  left:0;
}
ul.main li ul {
  border-top:0;
}
ul.main li ul li {
  float:left;
}
ul.main li a {
	height:2.5em;
	line-height:2.5em;
	border:0;
	color:#111;
	background:#fff;
}
ul.main li ul li a {
  width:12em;
  line-height:2em;
  height:2em;
  text-align:left;
  color:#fff;
  border-top:1px solid #444;
  background:#444;
}
ul.main li a:focus {color:#18d7e8; background:#fff;}
ul.main li ul li a:hover {
  color:#2044b9;
  background:#fff;
}
ul.main li:hover a {
  color:#2044b9;
  background:#fff;
}
ul.main li:hover ul li a {color:#111;}
ul.main li:hover ul li a:hover {color:#2044b9; background:#fff;}
ul.main li:hover a:active {background:#fff;}
ul.main li:hover ul li a:active {color:#2044b9; background:#fff;}
ul.main li.active a{color:#2044b9;}