Div Problemer

Hjemmesiden bliver vist rigtigt i IE men ikke i firefox. Kan det være et div problem, er min kode forkert?

Siden er www.ronkedor.com

Her er min stylesheet
/* Layout Stylesheet */

body {
margin:20px;
background:#ffffff;
color: #333333;
text-align:center;
padding:0;
}

#outer {
text-align:left;
border:1px solid #000000;
width:750px;
margin:auto;
}

#Topbilled {
text-align:center;
height:125px;
  background-image: url("../images/baggrundtop.jpg");
  }

#Menu {
text-align:center;
height:20px;
  background:#c9d8fc;
color: #333333;

border-width:px 0 0 0;
  }

#bodyblock {
    position:relative;
    background: #dcdcdc;
    color: #333333;
    width:750px;
    padding:0;
}



#Hovedside {
text-align:Left;
float:Right;
background:#e6e6e6;
color: #333333;
height:400px;
width:597px;
border:2px solid #e6e6e6;
background-image: url("../images/baggrund.jpg");
overflow:auto;
}

#Nyheder {
text-align:left;
float:Left;
height:400px;
width:145px;
background:#b9cdfb;
color: #333333;
border-style: solid;
border:2px solid #b9cdfb;
overflow:auto;
}


 
#Skoleinfo {
text-align:center;
background:#ffffff;
border-style: solid;
border:0px #000000;
width:750px;
height:20px;
margin:auto;
vertical-align:top;
}