Salve,
ho un problema col doctype che non capisco:
se inserisco il doctype nella pagina gli elementi header, menu-alto, container e footer hanno larghezze diverse, mentre se lo elimino le larghezze sono tutte uguali (come d'altronde specificato nel file css).

Allego il codice

-----------------------------------html--------------------------------
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/transitional.dtd">
<html>
<head>
<title> Homepage - Benvenuti</title>
<link rel="stylesheet" href="table.css" type="text/css">
</head>
<body>
<div id="header">
<div id="logo"></div>
<div id="prosa">
</div>
</div>
<div id="menu-alto">
</div>
<div id="container">
<div id="menu-verticale"></div>
<div id="contenitore-vuoto">
</div>
</div>
<div id="footer">
Copyright 2007 Inc. All Rights Reserved.
</div>
</body>
</html>
-------------------------------css--------------------------
html,body{
margin:0;
padding:0
}

body{
background:url(images/fade_blu.gif) repeat-x;
font:100.01% arial,sans-serif;
text-align:center;
}

h1,h2,h3,h4,h5,h6{margin-bottom: 0}


div#header{
clear:both;
width:752px;
height:138px;
margin-top: 10px;
text-align:center;
background: url(IMAGES/header.gif) no-repeat;
}

div#logo{
float:left;
margin-left:10px;
margin-top:25px;
width:125px;
height:83px;
background: url(IMAGES/logo_birre_01.gif) no-repeat;
}

div#prosa{
float:right;
margin-right:20px;
margin-top:50px;
font: Verdana;
font-size:11pt;
font-weight:bold;
font-style:italic;
color:#000080;
}

div#menu-alto{
clear:both;
width:752px;
height:49px;
margin-top:15px;
text-align:right;
background: url(IMAGES/strectch21.gif) repeat-x;
padding: 1em;
}


div#container{
clear:both;
margin:0 auto;
width:752px;
height:560px;
padding:5px;
text-align:left;
color:white;
font:Tahoma;
background-color:#000080
}



div#contenuto-vuoto{
float:right;
margin:10px;
width:541px;
height:400px;
padding:1em;
text-align:left;
color:white;
font-size:85%;
font:Tahoma;
}

div#footer{
clear:both;
width:752px;
height:49px;
margin-top:0px;
text-align:right;
font-size:70%;
padding-top:2em;
background: url(IMAGES/strectch21.gif) repeat-x;
}

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