CSS - 3-column Layout, Ie Not Positioning It Right

.leftColumn{
		margin-left:20px;
		width:100px;
		border:thin dotted #999999;
	}
	.middleColumn{
		margin-left:121px;
		width: 450px;
		border:thin dotted #999999;
	}
	.rightColumn{
		margin-left:572px;
		width: 200px;
		border:thin dotted #999999;
	}
	.main{
		left:200px;
		width: 950px;
		background-image: url(Images/PaperBkg.gif);
		background-repeat:repeat-y;
	}

        <div class="main">
		<div class="leftColumn">
		
		</div>

		<div class="middleColumn">					
		
		</div>
		
		<div class="rightColumn">
		
		</div>
         </div>

<div class="content">
    <div class="col1 column"></div>
    <div class="col3 column"></div>
    <div class="col2 column">
        <div class="header">Header</div>
    </div>
</div>

.column {
padding: 10px;
position:relative;
}

.header {
background:#cfe6f5;
color:#416383;
font-size:11px;
font-family:Arial;
font-weight:300;
padding-left:15px;
}

.col1 {
float: left;
width:250px;
}

.col2 {
margin-left: auto;
margin-right: auto;
}

.col3 {
float:right;
width:250px;
}

  	<!--begin wrapper-->
  	<div id="wrapper">
  
  	<!--begin side column -->
  	<div id="sideColumn">
        <span class="category">Products</span>
    <ul>
		<li><a href="/products/spirometers.html">Spirometers</a></li>
		<li><a href="/products/clinical_trials.html">Clinical Trials</a></li>
		<li><a href="/products/asthma_copd.html">Asthma & COPD</a></li>
		<li><a href="/products/smoking_cessation.html">Smoking Cessation</a></li>
		<li><a href="/products/resuscitaion.html">Resuscitation</a></li>
	</ul>
	
	<span class="category">Resources</span> 
    <ul>
      <li><a href="/resources/contact_us.html">Customer Support</a></li>
	  <li><a href="/resources/training_services.html">Training & Services</a></li>
      <li><a href="/resources/exhibitions.html">Exhibitions</a></li>
      <li><a href="/resources/newsletters.html">Newsletters</a></li>
      <li><a href="/resources/downloads.html">Downloads</a></li>
      <li><a href="/resources/useful_links.html">Useful Links</a></li>
      <li><a href="/resources/industry_information.html">Industry Information</a></li>
	  <li><a href="/resources/industry_information.html">Sitemap</a></li>
	</ul>
  </div>
  <!--end of side column -->
  
  <!--begin main column -->  
  <div id="mainColumn">
  
  	<!-- InstanceBeginEditable name="Main_Section" -->
  
  
  
    <div id="home">	
        <div id="scroll"><span>scrolling news will go hear and stop</span></div>
		
        <img src="/images/boys_bubbles.gif" width="485" height="333" alt="boys and bubbles" />
	
		<span class="large">Welcome to Vitalograph</span>
		
		<p>Vitalgraph offers a wide range of spirometers along with other asthma 
          management equipment with over 40 years experience. From simple hand-held 
          units to sophisticated Windows based spirometry systems, we have it 
          all. Check out our full line of respiratory equipment under the product 
          category.</p>
		
		
      <p><a href="/about_us/about_us.html">more about us...</a></p>
		
		
	</div>
  
  
  <!-- InstanceEndEditable -->
  
  </div>
  <!--end of main column -->
  
  </div> 
  <!--end of wrapper--> 

body {
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	font-size: 12px;
	text-align: center;
	background-color: #ffffff;
	color: #515151;
	margin:0px;
	padding:10px;
}

/*page container settings*/

#page {
	width: 750px;
	height: 600px;
	border: 1px solid #5094F9;
	background-color: #FFFFFF;
	overflow: hidden;
	margin: auto;
	padding: 10px 10px 10px 10px;
	text-align: left;
}

/*logo header and tag settings*/
	
#header {	
	margin: 0;
	padding-bottom: 5px;
	width: 450px;
	height: 36px;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	color: #5094F9;
	text-align: left;
}

#header img {
    vertical-align: -7px;
    }

.tagline {
	color: #5094F9;
	font-size: 16;
	font-style: italic;
	font-weight: bold;
	display: inline;
	clear: both;
	line-height: 20px;
	margin-left: 10px;
}

/*top bar settings*/

#topbar {
	float: top;
	height: 20px;
	background-color: #5094f9;
	clear: both;
	padding-left: 10px;
	text-align: left;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	color: #FFFFFF;
	font-size: 12px;
	font-weight: bold;
}

#topbar a:link, #topbar a:visited {
	background-color: inherit;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	text-decoration: none;
	color: #FFFFFF;
	font-size: 12px;
	font-weight: bold;
}

#topbar a:hover, #topbar a:active {
	background-color: #FFFFFF;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	text-decoration: none;
	color: #5094F9;
	font-size: 12px;
	font-weight: bold;
}

#topbar ul {
	list-style: none;
	margin: 0;
	padding-top: 2px;
}

#topbar li {
	display: inline;
	margin-right: 160px;
}

/*Main Section two columns under top section*/

#wrapper{
	padding: 10px 10px 10px 0px;
	width: 100%;
	height: 100%;
}

#sideColumn {
	float:left;
	width:155px;
	height: 78%;
	background-color: #5094F9;
	padding-top: 50px;
	padding-left:10px; 
	padding-bottom:10px;
	pading-right: 10px;
	margin-right: 10px;
	text-align: left;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	color: #FFFFFF;
	font-weight: bold;
	line-height: 20px;
}

.category {
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	color: #FFFFFF;
	font-size: 16px;
	font-weight: bold;
	letter-spacing: 5px;
}

#sideColumn a:link, #sideColumn a:visited {
	background-color: inherit;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	text-decoration: none;
	color: #FFFFFF;
	font-size: 12px;
	font-weight: bold;
}

#sideColumn a:hover, #sideColumn a:active {
	background-color: #FFFFFF;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	text-decoration: none;
	color: #5094F9;
	font-size: 12px;
	font-weight: bold;
}

#sideColumn ul {
	list-style: none;
	padding: 15px 0px 15px 10px;
	margin: 0px;
}

#mainColumn {
	padding: 0px;
}

/*footer*/

.footer {
	font-family: "Times New Roman", Times, serif;
	font-size: 9px;
	color: #999999;
}

/*text*/

.large {
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	color: #5094F9;
	font-size: 18px;
	font-weight: bold;
	margin-bottom: 15px;
}

/*home page*/

#home {
	margin: auto;
}

#home img {
	margin: 5px auto 5px auto;
}

#home p, .large {
	margin: auto 40px auto 40px;
}

#home a:link, #home a:visited {
	background-color: inherit;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	text-decoration: none;
	color: #5094F9;
	font-size: 12px;
	font-weight: bold;
}

#home a:hover, #home a:active {
	background-color: inherit;
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	text-decoration: none;
	color: #990099;
	font-size: 12px;
	font-weight: bold;
}

#scroll {
	width: 560px;
	padding: 5px;
	background-color: inherit;
	border: 1px solid #5094F9;
	margin-bottom: 5px;
}