Certo, riporto il codice HTML e CSS, grazie 1000

Codice PHP:
CTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title></title>
        <link rel="stylesheet" href="css/style.css" type="text/css" />
        <script language="javascript">AC_FL_RunContent = 0;</script>
        <script src="AC_RunActiveContent.js" language="javascript"></script>
    </head>
    <body>
        <div id="masterContainer">
            <div id="header">
                <div class="headerLeft">
                    <div class="blueBarMenu"></div>
                </div>
                <div class="headerRight">
                    <div id="menu">
                        <a class="lnkMenu" href="#">
                            Home
                        </a>
                        <div class="arrowMenu">
                            [img]images/arrow.gif[/img]
                        </div>
                        <a class="lnkMenu" href="#">
                            Chi Siamo
                        </a>
                        <div class="arrowMenu">
                            [img]images/arrow.gif[/img]
                        </div>
                        <a class="lnkMenu" href="#">
                            Galleria Foto
                        </a>
                        <div class="arrowMenu">
                            [img]images/arrow.gif[/img]
                        </div>
                        <a class="lnkMenu" href="#">
                            Offerte
                        </a>
                        <div class="arrowMenu">
                            [img]images/arrow.gif[/img]
                        </div>
                        <a class="lnkMenu" href="#">
                            Marchi
                        </a>
                        <div class="arrowMenu">
                            [img]images/arrow.gif[/img]
                        </div>
                        <a class="lnkMenu" href="#">
                            Contatti
                        </a>
                    </div>
                </div>
            </div>
            <div class="breakBar"></div>
            <div id="spot">


                <div class="slide">
                    <script language="javascript">
                        if (AC_FL_RunContent == 0) {
                            alert("Questa pagina richiede AC_RunActiveContent.js.");
                        } else {
                            AC_FL_RunContent(
                                'codebase', 'http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0',
                                'width', '578',
                                'height', '256',
                                'src', 'swf/slide',
                                'quality', 'high',
                                'pluginspage', 'http://www.macromedia.com/go/getflashplayer',
                                'align', 'middle',
                                'play', 'true',
                                'loop', 'true',
                                'scale', 'showall',
                                'wmode', 'window',
                                'devicefont', 'false',
                                'id', 'swf/slide',
                                'bgcolor', '#cccccc',
                                'name', 'swf/slide',
                                'menu', 'true',
                                'allowFullScreen', 'false',
                                'allowScriptAccess','sameDomain',
                                'movie', 'swf/slide',
                                'salign', ''
                                ); //end AC code
                        }
                    </script>
                    <noscript>
                        <object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="578" height="256" id="swf/slide" align="middle">
                        <param name="allowScriptAccess" value="sameDomain" />
                        <param name="allowFullScreen" value="false" />
                        <param name="movie" value="swf/slide.swf" /><param name="quality" value="high" /><param name="bgcolor" value="#cccccc" />    <embed src="swf/slide.swf" quality="high" bgcolor="#cccccc" width="578" height="256" name="swf/slide" align="middle" allowScriptAccess="sameDomain" allowFullScreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" />
                        </object>
                    </noscript>
                </div>




            </div>
            <div id="container">
                <div class="containerLeft">
                    <div class="contLeft01">
                        <div class="contLeft01Left">
                            Lorem conseter lorem conseter dolor sit amet,  sed diam  elitr, sed diam Lorem ipsum dolor sit
                        </div>
                        <div class="contLeft01Right">
                            [img]images/vasca01.jpg[/img]
                        </div>
                    </div>
                    [img]images/vetrina1.jpg[/img]
                </div>
                <div class="containerRight">
                    
                    <div class="contRightTitle">
                        Servizi
                    </div>
                    <div class="contRight01">
                        <div class="contRight01Left">
                            [img]images/servizi1.jpg[/img]
                        </div>
                        <div class="contRight01Right">
                            Lorem conseter lorem conseter dolor sit amet,  sed diam  elitr, sed diam Lorem ipsum dolor sit Lorem conseter lorem conseter do
                        </div>
                    </div>
                    
                    <div class="breakBar"></div>
                    
                    <div class="contRightTitle">
                        Prodotti
                    </div>
                    <div class="contRight01">
                        <div class="contRight01Left">
                            [img]images/prodotti1.jpg[/img]
                        </div>
                        <div class="contRight01Right">
                            Lorem conseter lorem conseter dolor sit amet,  sed diam  elitr, sed diam Lorem ipsum dolor sit Lorem conseter lorem conseter do
                        </div>
                    </div>
                    
                </div>
                
            </div>
            
            <div class="breakBar"></div>
            
            <div id="footer">
                © 2010 - tutti i diritti riservati
            </div>
        </div>
    </body>
</html> 
Codice PHP:
body {
    background: url(../images/bg01.gif) repeat-x top;
    margin: 0;
}

#masterContainer{
    width: 978px;
    margin: 0 auto;
}

#header{
    height: 63px;
}

.headerLeft{
    float: left;
    width: 400px;
    padding-top: 21px;
}

.headerRight{
    width: 563px;
    float:right;
    text-align: left;
}

.blueBarMenu{
    background: #3366cc;
    height: 30px;
}

#menu{
    padding-top: 5px;
}

.breakBar{
    background: #cccccc;
    width: 100%;
    height: 3px;
    margin: 5px 0;
    display: block;
    clear: both;
}

.lnkMenu{
    font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
    text-transform: uppercase;
    float: left;
    line-height: 60px;
    color: #3366cc;
    font-size: 12px;
    text-decoration: none;
}

.lnkMenu:hover{
    color: #ff6600;
}

.lnkMenu:hover{
    background: url(../images/hoveritem.jpg) top center no-repeat;
    background-position-y: 8px;
}

.arrow{
    margin: 29px 14px 0;
    float: left;
}

#spot{
    width: 978px;
    height: 256px;
    background: url(../images/spot.jpg);
}

.slide{
    float: right;
}

#container{
    font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
    color: #666666;
    text-align: justify;
    font-size: 10px;
    margin-top: 15px;
    display: block;
    clear: both;
}

.containerLeft{
    float: left;
    width: 400px;
}

.containerLeft01{

}

.contLeft01Left{
    width: 220px;
    float: left;
}

.contLeft01Right{
    float: right;
}

.containerRight{
    float: right;
    width: 563px;
}

.contRightTitle{
    width: 568px;;
    font-size: 16px;
    color: #666666;
    text-transform: uppercase;
    display: block;
    clear: both;
    margin-bottom: 10px;
}

.contRight01{
    height: 107px;
}

.contRight01Left{
    float: left;
}

.contRight01Right{
    width: 380px;
    text-align: justify;;
    float: right;
}

.evident{
    font-weight: bold;
    color: #216e84;
}

.img1{
    margin-top: 10px;
}

#footer{
    font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
    color: #999999;
    font-size: 12px;
    text-align: center;
} 
Il problema è che il breakBar in basso mi andava a sovrapporsi al container come se l'altezza del container non esistesse.

Il problema di sovrapposizione l'ho risolto inserendo in .breakBar: display:block; clear: both;
Così in questo modo non si sovrappone più, ma se al breakBar vado a dare un margin-top il margine mi parte dalla parte alta del container.

In sostanza, se il container, in base al contenuto, è diventato alto 500, ad esempio, per dare al breakBar un margine di 15 dovrò scrivere margin-top: 515px;

Non so, è come se fosse annullata l'altezza e il contenuto non "riempia" il div. bho!