Continua ad esserci qualcosa che mi sfugge...
:rollo:

Ho provato ad applicare il tuo esempio (che di per sé funziona in una prova a parte che ho fatto) al mio layout, ma evidentemente qualcosa è andato storto... e non capisco cosa.

Ti riporto l'intero foglio di stile:

/* GENERALE */
html, body {
text-align: center;
background-color: #BACEEB;
margin: 10px 0px 10px 0px;
padding: 0px;
}
div, a {
line-height: 14px;
text-align: left;
font-family: Verdana, Arial, Helvetica, sans-serif;
font-size: 11px;
color: #000000;
}
strong {
color: #3F69A6;
}
/* LINK */
a {
text-decoration: none;
}
a:hover {
text-decoration: underline;
}
a:visited {
color: #666666;
}
div#colright a {
font-size: 9px;
color: #EE1A26;
}
div#colright a:hover {
color: #F57A81;
}
div#colright a:visited {
color: #9E0C13;
}
div#signature a {
font-size: 9px;
color: #3F69A6;
}
div#signature a:hover {
text-decoration: overline underline;
}
div#signature a:visited {
color: #3F69A6;
}
/* STRUTTURA COLONNE */
div#box {
width: 720px;
margin: 0px auto 0px auto;
}
div#head {
width: 720px;
height: 160px;
background-image:url(../titles/title.gif);
background-position: center center;
background-repeat: no-repeat;
margin-bottom: 6px;
}
/* BOX */
div#top {
width: 720px;
height: 25px;
background-image: url(../titles/bgtop.gif);
background-repeat: no-repeat;
background-position: center;
}
div#center {
width: 720px;
height: 700px;
background-color: #E5EAF4;
}
div#bottom {
width: 720px;
height: 25px;
background-image: url(../titles/bgbottom.gif);
background-repeat: no-repeat;
background-position: center;
clear: both;
position: relative;
}
/* COLONNA SINISTRA */
div#colleft {
text-align: justify;
padding: 35px 60px 35px 60px;
width: 350px;
float: left;
background-color: #FFFFFF;
}
div#colleft p {
margin: 0px 0px 8px 0px;
}
div#colleft img {
margin-bottom: 8px;
clear: both;
display: block;
}
/* COLONNA DESTRA */
#colright {
font-size: 9px;
font-size: 9px;
text-align: justify;
width: 190px;
background-color: #E5EAF4;
padding: 5px 30px 5px 30px;
float: left;
}
div#colright img {
margin-bottom: 8px;
display: block;
clear: both;
}
/* SIGNATURE */
div#signature {
color: #FFFFFF;
font-size: 9px;
text-align: center;
clear: both;
position: relative;
top: 10px;
bottom: 10px;
}