Ciao a tutti,
vi allego uno screenshot di quello che mi succede alla pagina:
nel file php includo il menu:
codice:
 <?php 
//echo "Sei loggato come: " . $_SESSION['user'];
echo "<div id=\"menu\">
	<a href=\"./team.php\">Squadra</a>
	<a href=\"./formazione.php\">Formazione</a>
	<a href=\"./bacheca.php\">Bacheca</a>
	<a href=\"./logout.php\">Logout</a>";
	if(strcmp($_SESSION['user'], "xxxxxxx") == 0){
		echo "<a href=\"./registration.php\">Registra utenti</a>";
	}
echo "</div>";
?>
Come vedete ho commentato la echo che mi causa il problema. Se è decommentata il layout è a posto, se come in questo caso è decommentata fa lo scherzo dell'allegato.

Il css:
codice:
html, body{
	width:100%;
	height:100%;
	margin: 0 0 0 0px;
	padding: 0px;
	background: url("../images/banner.png") no-repeat top;
	background-color: #3fc26e;
	font-size: 14px;
	font-family: Verdana, Arial, "MS Trebuchet", sans-serif;
}


#main{
	width:auto;
	height: auto;
	margin-left:auto;
	margin-right:auto;
	text-align: center;
}

#menu{
	width: 600px;
	height: 40px;	
	margin-top:135px;
	margin-left:auto;
	margin-right:auto;
}

#menu a{
	text-decoration: none;
	color: black;
	font-size: 18px;;
	display: block;
	height: 26px;
	width: 100px;
	float:left;
	padding: 5px;
	margin-left: 10px;
	margin-right: 10px;
	text-align:center;
}

#team_box{
	width:300px;
	border: 2px solid blue;
	float:left;
}

#module_box{
	width:440px;
	border: 2px solid blue;
	text-align:center;
	float:left;
	background: url('../images/bg2.png') repeat;
}

#prob_team_box{
	width:auto;
	border: 2px solid blue;
	text-align:center;
	float:left;
	font-size:10px;
	font-family: Verdana, Arial, "MS Trebuchet", sans-serif;
	
}

.prob_match{
	font-size: 14px;
	font-weight: bold;
}

.player_sx{
	border-bottom: 1px solid;
	width:100px;
	text-align: left;
	float:left;
}

.player_dx{
	border-bottom: 1px solid;
	width:100px;
	text-align: right;
	float:left;
}
.login{
	height:300px;
	width:500px;
	margin-left:auto;
	margin-right:auto;
	text-align: center;
	font-family: Verdana, Arial, "MS Trebuchet", sans-serif;
	font-size:14px;
}

.login_input{
	height:24px;
	width: 240px;
	font-family: Verdana, Arial, "MS Trebuchet", sans-serif;
	font-weight: bold;
	font-size:12px;
	border: 3px solid #887777;
	color: #887777;
	margin-top:10px;
	margin-bottom:10px;
	background-color: #ccdddd;
}

.login_error{
	width: 300px;
	color: #880000;
	font-family: Verdana, Arial, "MS Trebuchet", sans-serif;
	font-weight: bold;
	font-size:14px;
	text-align:center;
	border: 3px solid #880000;
	padding:5px;
	margin-left:auto;
	margin-right:auto;
	margin-bottom:20px;
}

.title{
	text-align:center;
	font-size: 200%;
	text-decoration: underline;
}

.role{
	height:30px;
	color: green;
	font-size:16px;
	background-color: #99CC66;	
	border-bottom:1px solid black;
}

.team{
	width: 10%;
	font-style: italic;
	display: inline-block;
	text-align: left;
}

.team_table{
	border:3px solid green;
}

.player{
	width:80%;
	text-align:left;
	display: inline-block;
	text-align: left;
}

#full_team{
	width:400px;
	margin-left:auto;
	margin-right:auto;
}

.entry1{
	background-color: #CCFFCC;	
	border-bottom: 1px solid black;
}

.entry2{
	background-color: #CCFF99;
	border-bottom: 1px solid black;
}

.mex1{
	background-color: #CCFFCC;	
	border-bottom: 1px solid black;
}

.mex2{
	background-color: #CCFF99;
	border-bottom: 1px solid black;
}

.all_message{
	float: left;
	width: 600px;
}

.modules{
	height: 24px;
	text-align: center;
	font-size: 14px;
	border: 2px solid green;
	margin-left:10px;
	margin-right:10px;
	cursor: pointer;
}

.choose_player{
	float:left;
	width:200px;
	font-size: 90%;
	text-align: center;
}

.full_team{
	height:350px;
}

.bench{
	float:right;
	margin-right:10px;
}

.titolari{
	float:left;
	margin-left:10px;
}

.submit_team, .login_button, .submit_mex{
	height: 24px;
	text-align: center;
	font-size: 14px;
	border: 3px solid green;
	margin-top:10px;
	margin-left:10px;
	margin-right:10px;
}

.write_mex{
	font-family: Verdana, Arial, "MS Trebuchet", sans-serif;
	font-size:14px;
	border: 3px solid #887777;
	color: #887777;
	margin-top:10px;
	margin-bottom:10px;
	background-color: #ccdddd;
}
.small_nb{
	font-size:70%;
	color: #999999;
	font-style: italic;
	
}
E questo è uno dei file php dove includo il menu:
Codice PHP:
<?php
include("./common/header.php");
if(!isset($_SESSION["user"])){
        echo "Devi eseguire il login per accedere alla tua squadra.

            Torna alla <a href=\"./index.php\">pagina principale</a> ed effetua il login.";
    }
    else{    
        include("./common/menu.php");
        include("./common/lib/lib.php");
        echo "<div id=\"main\"><div id=\"full_team\">";
            load_team($_SESSION["user"]);
        echo "</div></div>";
    }
require_once("./common/footer.php");
?>
La cosa strana è che prima di loggarsi la pagina index non presenta il problema, mentre dopo il login si:
Codice PHP:
 <?php
require_once("./common/header.php");

    if(!isset($_SESSION['user'])){
        include("./login.php");
    }
    if(isset($_SESSION['user'])){
        require_once("./common/menu.php");
    }
require_once("./common/footer.php");
?>
Non riesco a capire cosa causa questo problema.
Grazie a chi cercherà di aiutarmi!