Menu items in header region

I add code in header:
/**

 print '<h1><a href="'. check_url($base_path) .'" title="'. check_plain($site_name) .'">';
            if ($logo) {
              print '<img src="'. check_url($logo) .'" alt="'. check_plain($site_name) .'" id="logo" />';
            }
            if ($site_name) {
              print '<span id="name">'. check_plain($site_name) .'</span>';
            }
            if ($site_slogan) {
              print '<span id="slogan">'. check_plain($site_slogan) .'</span>';
            }
            print '<span class="clear"></span></a></h1>';
          

**/
and in file style.css i add:
#primary a {

margin: 0 5px 0 0;
border: solid #6191C5 1px;
border-width: 1px 1px 0 1px;
}

#primary ul {
margin: 0;
padding: 0;
list-style: none;
display: block;
}

#primary ul li {
margin: 0 0px 0 0;
padding: 0;

display: block;
float: left;
}

#primary li a {
color: #FFFFFF;
display: block;
padding: 0 10px;

text-transform: uppercase;

font-weight: bold;
padding: 6px 0px;
text-decoration: none;
background-image:url(images/roundedge-red-right.gif);

}

#primary li a:hover,
#primary li a:active,
#primary li a:focus {
color: #FF0000;
background-image:url(images/roundedge-blue-right.gif);
}

#primary li a.active {
color: #FFFFFF;
background: #333333;
}
#secondary
{

font-weight:bold;
font-size:14px;

}
#secondary li a:hover,
#secondary li a:active,
#secondary li a:focus {
color: #FF0000;
background-image:url(images/roundedge-blue-right.gif);
}
#secondary li a {
color:#330000;

padding: 0 10px;
font-weight: bold;
padding: 6px 0px;
text-decoration: none;
}
In firefox Item menu works well. but in IE6 when i am restore Down for brower then item menu row down .http://timbandocthan.com/Dp5U_NFlash/