problema centrare div e ul

[Progeny]

div#header {
  width: 100%;
  background-color: #F4F4F4;
  border: 1px solid #3B88C5;
  padding-top: 10px;
}

div#header .logo {
  float: left;
}

div#header .banner {
  float: right;
  margin-right: 20px;
}

div#header .menu {
  float: none;
  clear: both;
  width: 100%;
  padding-top: 10px;

  text-align: center;
  margin: 0 auto;
}

div.cleaner {
  float: none;
  clear: both;
}

/* Header Navigation Menu */
#nav {
  margin: 0px;
  padding: 0px 0px 20px 10px;
}

#nav li {
  margin: 0px;
  padding: 0px;
  display: inline;
  list-style-type: none;
}

#nav a:link, #nav a:visited {
  float: left;
  font-size: 10px;
  line-height: 14px;
  font-weight: bold;
  padding: 0 12px 6px 12px;
  text-decoration: none;
  color: #3B88C5;
}

#nav a:hover {
  color: #FF9C00;
  background: url(../images/css/tab_rounded.png) no-repeat bottom center;
} 

<div id="header">

  <div class="logo">
    [img]images/logo/default.png[/img]
  </div>

  <div class="banner">
    <script type="text/javascript" src="http://impit.tradedoubler.com/imp?type(js)pool(80288)a(1101311)" charset="ISO-8859-1"></script>
  </div>

  <div class="menu">
    <ul id="nav">[*][url="index.php"]<span>Home Page</span>[/url][*][url="chat.php"]<span>Chat</span>[/url][*][url="index.php?mod=forum"]<span>Forum</span>[/url][*][url="index.php?mod=online"]<span>Utenti OnLine</span>[/url][*][url="index.php?mod=searchuser"]<span>Cerca</span>[/url][*][url="index.php?mod=gallery"]<span>Photo Gallery</span>[/url][*][url="#"]<span>Profilo</span>[/url][*][url="index.php?mod=mail"]<span>Messaggi Privati</span>[/url][*][url="index.php?mod=options"]<span>Opzioni</span>[/url]
      <?php if(isset($usr)) { ?>[*][url="logout.php"]<span>Logout</span>[/url]
      <?php } ?>[/list]
  </div>

</div>

non riesco a centrare (orizzontalmente) il div "menu", la pagina è http://www.baricity.it/index2.php
le ho provate tutte, text-align: center, margin: 0 auto; <div align="center"> ma niente... googlato e cercato sui forum ma non riesco
qualcuno riesce a darmi una mano?

[Sky]

Io lo vedo centrato sia con Firefox che con Internet Explorer 6 :P

[Progeny]

si ho risolto, il problema era in float: left; presente per i tag <a>