css3, cannot put a div centralized - html

Question

I cannot put my menu in the center of the page, i've inserted all "margin: 0 auto;" i can and all "text-align: center", and the div is separated from everything, is not a child of something else..
here's the css code:
.more{
margin: 0 auto;
position:relative;
clear:both;
font-size: 13px;
padding: 20px 0px;
text-transform: uppercase;
width: 40%;
height: 20%;
}
.more ul{
display:block;
text-align:center;
}
.more ul li{
display: block;
padding: 10px 3px;
float:left;
}
.more ul li.selected a,
.more ul li.selected a:hover{
background:#0099c5;
color:#fff;
text-shadow:none;
font-weight:bold;
}
.more ul li a{
color:#555;
float:left;
background:#fff;
width: 100%;
padding: 8px 10px;
-moz-box-shadow:1px 1px 2px #aaa;
-webkit-box-shadow:1px 1px 2px #aaa;
box-shadow:1px 1px 2px #aaa;
}
.more ul li a:hover{
background:#000;
color:#fff;
}
And here's the HTML code:
<div class="more">
<ul>
<li class="selected">Homepage Blog</li>
<li>Cerca</li>
<li>Archivio</li>
<li>Tags</li>
</ul>
</div>
How-to make the div permanently in the center of my page? I've tried lot, lot, lot of possible moves.
Thank you.
p.s. I've also tried to put a <div align=center> ...my menu (class=more) list ...</div>

Answer 1

Remember that you can't use margin:0 auto on floatted element.
Keys for margin 0 auto are:
1) element must have display:block
2) no float, absolute or fixed position
.more{
float:left;
clear:both;
font-size: 13px;
padding: 20px 0px;
text-transform: uppercase;
width: 100%;
height: 20%;
}
.more ul{
display:block;
text-align:center;
margin:0 auto;
}
.more ul li{
display: inline-block;
padding: 10px 3px;
}
.more ul li.selected a,
.more ul li.selected a:hover{
background:#0099c5;
color:#fff;
text-shadow:none;
font-weight:bold;
}
.more ul li a{
color:#555;
background:#fff;
width: 100%;
padding: 8px 10px;
-moz-box-shadow:1px 1px 2px #aaa;
-webkit-box-shadow:1px 1px 2px #aaa;
box-shadow:1px 1px 2px #aaa;
}
.more ul li a:hover{
background:#000;
color:#fff;
}