ciao
http://www.pubdiroma.it/prova/prova.htm

con ie l'immagine che non si vede in alto sx (non si vede semplicemente perchè online non c'è) si posiziona bene e si sovrappone per un pezzo al livello in grigio che sta sotto. con firefox, invece mi sposta il livello in grigio più sotto.
Inoltre le immagini del w3c e la scritta bla bla bla dovrebbero stare in basso come si vde su IE 7.0

mi date una mano?
il css:
codice:
*
{
	margin: 0;
	padding: 0;
}
.linkArea
{ color:#f31e24}
.linkArea a
{ color:#f31e24}

.inte
{
	display: block;
	padding: 7px 0 7px 20px;
	width: 279px;
	text-decoration: none;
	color: #333;
	background: #FC0;
}
.testataArticolo
{ background-color:#333;color:white; font-weight:bold}
.testataArticoloSX
{ color:yellow; float:left}

.testataArticoloDX
{  float:right; font-weight:bold;font-size:0.9em}


.bottom
{
	clear: both;
}

body
{
	margin: 0;
	padding: 0;
	background-image:url('images/mess.gif');
	color: #000;
	font-size: 80%;
	font-family: "arial";
}

img
{
	border: 0;
}

#topCont
{
	width: 100%;
	height: 190px;
	color: #CCC;
	z-index:2
}

#top
{
	margin: 0 auto;
	width: 900px;
	height: 50px;
	background: #000;
	font-weight: bold;
	z-index:1;
}

#topleft
{
	float: left;
	width: 133px;
	font-size: 85%;
	padding:  2px 0 0  25px;
	color: #666;
	height: 126px; 
	z-index: 3;
	position:relative;
	top: 0px;
	left: 0px;
}

#topleft a
{
	color: #FC0;
	text-decoration: none;
}

#topleft a:hover
{
	color: #FFF;
	text-decoration: none;
}

#topright
{
	float: left;
	width: 715px;
	height: 34px;
	padding: 16px 25px 0 0;
	text-align: right;
	font-size: 120%;
	color: #999;
}

#header
{
	margin: 0 auto;
	width: 900px;
	height: 140px;
	background: #000;
	z-index:4
}

#headerleft
{
	float: left;
	width: 300px;
	height: 140px;
	background: #333;
	z-index:5;
	clear:both
}

#headerright
{
	float: left;
	width: 600px;
	height: 140px;
	background: #333;
}

#headerleft h1
{
	margin: 0;
	padding: 25px 30px 0 0;
	font-weight: normal;
	font-size: 300%;
	letter-spacing: -2px;
	color: #FFF;
	text-align: right;
}

#headerleft h2
{
	margin: -10px 0 0 0;
	padding: 0 30px 0 0;
	font-weight: normal;
	font-size: 200%;
	letter-spacing: -1px;
	color: #FC0;
	text-align: right;
}

#mainCont
{
	width: 100%;
}

#main
{
	margin: 0 auto;
	width: 900px;
	background: #FFF url('images/sfondo_principale2.png') repeat-y;
}

#mainmenu
{
	float: left;
	width: 299px;
	padding: 15px 0 0 0;
	font-size: 85%;
	font-weight: bold;
	background: #f1f1f1;
}

#mainmenu ul
{
	list-style-type: none;
	margin: 0 0 30px 0;
}

#mainmenu a
{
	display: block;
	padding: 7px 0 7px 20px;
	width: 279px;
	text-decoration: none;
	color: #333;
	background: #FC0;
	

}

#mainmenu a.active
{
	background: #333;
	color: #FFF;
}

#mainmenu a:hover
{
	background: #FC0;
	color: #FFF;
}

#mainmenu p
{
	margin: 0 20px 15px 20px;
	color: #555;
	line-height: 160%;
	font-size: 110%;
}

#mainmenu p span
{
	color: #222;
	font-size: 125%;
}

#maincontent
{
	float: left;
	width: 550px;
	padding: 15px 25px 0 25px;
	line-height: 160%;
}

#maincontent p
{
	margin: 0 0 15px 0;
	padding: 0;
}

#maincontent h1
{
	margin: 0 0 15px 0;
	padding: 0;
	font-weight: normal;
	font-size: 170%;
	color: #666;
}

#maincontent img
{
	float: right;
	margin: 0 0 15px 15px;
	padding: 5px;
	border: 1px solid #CCC;
}

#maincontent ul
{
	margin: 0 0 15px 30px;
	list-style-type: square;
	color: #FC0;
}

#maincontent blockquote
{
	margin: 0 0 15px 20px;
	padding: 0 0 0 15px;
	border-left: 3px solid #FC0;
}

#maincontent ul li span
{
	color: #000;
}

#footerCont
{
	width: 100%;
}

#footer
{
	margin: 0 auto;
	width: 900px;
	color: #999;
	font-size: 85%;
	background: #FFF;
	border-top: 1px solid #CCC;
}

#footer a
{
	color: #666;
	text-decoration: none;
}

#footer a:hover
{
	color: #FC0;
}

#footerleft
{
	float: left;
	width: 425px;
	padding: 15px 0 15px 25px;
}

#footerright
{
	float: left;
	width: 425px;
	padding: 15px 25px 15px 0;
	text-align: right;
}
grazie