页面布局错位，怎么回事？

[cherishF21]

代码如下：
</div>
<div id="nava6">
<ul id="nav6txt" >

<li class="auto-style6"><img src="../imgs/9.png" /></li>
<li class="flagss"><img src="../imgs/9.png" /></li>
<li class="nav6a"><a href="../user/Contact.aspx" >会教会做</a></li>
<li class="nav6b">|</li>
<li class="nav6a"><a href="../huijiang/jianghua.aspx">会讲</a></li>
<li class="nav6b">|</li>
<li class="nav6a"><a href="../huisixiang/sixiang.aspx">会思想工作</a></li>
<li class="nav6b">|</li>
<li class="nav6a"><a href="../liuyan/bbs.aspx">留言板</a></li>
<li class="nav6b">|</li>
<li class="nav6a"><a href="../xiazai/xiazai.aspx">教案下载</a></li>
</ul>
</div>
<div id="nav6" style="height :auto ">
<asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server" >

</asp:ContentPlaceHolder>
CSS是：

#nava6{
border:0px solid #ff0000;
height:60px;
line-height:60px;
background-image:url(../imgs/背景用图1.png);
margin:auto;

}
#nav6txt{
list-style:none;
}
#nav6txt li{
border:0px solid #ff0000;
font-size:20px;
color:black;
}
.flags{
width:200px;
float:left;
padding-left:400px;
}
.flagss{
width:380px;
float:right;
}
.nav6a{
width:180px;
text-align:center;
float:left;
}
.nav6b{
width:20px;
text-align:center;
float:left;
color:black;
}

[街头小贩]

查看页面源码看一看是否有红色的字符。如果有哪证明标签非正常闭合。 如果没有多数是样式问题