Blog bug. Needs help

I still haven’t figured out why the ‘Home’ link in the top navigation overlaps with the green horizontal dotted lines when I’m in the homepage, but works find in other pages.

I can’t find any difference in the PHP code between the homepage and other pages. Even in the CSS code that formats the top navigation, I can’t find something unique to the homepage.

#topnav {
  position: relative;
  height: 45px;
  width: 100%;
  background: url(./dots-horiz.gif) transparent repeat-x bottom;
}

#topnav div {
  position: absolute;
  bottom: 0;
  right: 0;
}

#topnav ul {
  list-style: none;
}

#topnav li {
  float: left;
  padding: 1px 0 0 5px;
  margin: 0 0 0 10px;
}

#topnav a {
  font-size: 12px;
  font-family: Arial;
  padding: 0 5px 0 5px;
  font-weight: bold;
  text-decoration: none;
}


body#home #home_tab a,
body#report #report_tab a,
body#article #article_tab a,
body#archive #archive_tab a,
body#contact #contact_tab a {
  text-decoration: none;
  color: #600;
}

body#home #home_tab,
body#report #report_tab,
body#article #article_tab,
body#archive #archive_tab
body#contact #contact_tab {
  background: #fff;
}