Can someone tell me what is wrong with css header code to fix for IE?

[improveit4]

In all browsers other than IE the header image is centered over the nav & main content area. In IE it is pushed to the left.

/* CSS Document */

body  {
	font: 100% Verdana, Arial, Helvetica, sans-serif;
	background: #666666;
	background-color: #081934;
	margin: 0; /* it's good practice to zero the margin and padding of the body element to account for differing browser defaults */
	padding: 0;
	text-align: center; /* this centers the container in IE 5* browsers. The text is then set to the left aligned default in the #container selector */
	color: #000000;
}
.twoColFixLtHdr #container { 
	width: 850px;  /* using 20px less than a full 800px width allows for browser chrome and avoids a horizontal scroll bar */
	height: 640px;
	background: #FFFFFF;
	margin: 0 auto; /* the auto margins (in conjunction with a width) center the page */
	border: 1px solid #000000;
	text-align: left; /* this overrides the text-align: center on the body element. */
	background-image: url(images/bkgrnd.jpg);
} 
.twoColFixLtHdr #header {
	background: none;
	padding: 20px 0px 0px 45px;  /* this padding matches the left alignment of the elements in the divs that appear beneath it. If an image is used in the #header instead of text, you may want to remove the padding. */
	position:absolute;
	width: 807px;
} 
.twoColFixLtHdr #header h1 {
	margin: 20; /* zeroing the margin of the last element in the #header div will avoid margin collapse - an unexplainable space between divs. If the div has a border around it, this is not necessary as that also avoids the margin collapse */
	padding: 10px 0; /* using padding instead of margin will allow you to keep the element away from the edges of the div */
}
.twoColFixLtHdr #sidebar1 {
	float: left; /* since this element is floated, a width must be given */
	width: 120px; /* the actual width of this div, in standards-compliant browsers, or standards mode in Internet Explorer will include the padding and border in addition to the width */
	background: none; /* the background color will be displayed for the length of the content in the column, but no further */
	padding: 60px 0px 0px 47px;
}
.twoColFixLtHdr #mainContent { 
	margin: 0 0 0 0px; /* the left margin on this div element creates the column down the left side of the page - no matter how much content the sidebar1 div contains, the column space will remain. You can remove this margin if you want the #mainContent div's text to fill the #sidebar1 space when the content in #sidebar1 ends. */
	padding: 65px 0 0px 20px; /* remember that padding is the space inside the div box and margin is the space outside the div box */
} 
.twoColFixLtHdr #footer { 
	padding: 0 10px 0 20px; /* this padding matches the left alignment of the elements in the divs that appear above it. */
	background:#DDDDDD; 
} 
.twoColFixLtHdr #footer p {
	margin: 0; /* zeroing the margins of the first element in the footer will avoid the possibility of margin collapse - a space between divs */
	padding: 10px 0; /* padding on this element will create space, just as the the margin would have, without the margin collapse issue */
}
.fltrt { /* this class can be used to float an element right in your page. The floated element must precede the element it should be next to on the page. */
	float: right;
	margin-left: 8px;
}
.fltlft { /* this class can be used to float an element left in your page */
	float: left;
	margin-right: 8px;
}
.clearfloat { /* this class should be placed on a div or break element and should be the final element before the close of a container that should fully contain a float */
	clear:both;
    height:0;
    font-size: 1px;
    line-height: 0px;
}

____________________________________________

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Untitled Document</title>

<link href="style.css" rel="stylesheet" type="text/css" />
</head>

<body class="twoColFixLtHdr">
<div id="container">
  <div id="header">
    <img src="http://bytes.com/images/plan_header.png" alt="plan" name="plan_banner" width="759" height="51" border="0" id="plan_banner" />
  <!-- end #header --></div>
  <div id="sidebar1">
    <p><a href="plan.html"><img src="http://bytes.com/images/plan_icon.png" alt="plan" name="plan_icon" width="98" height="131" border="0" id="plan_icon" /></a></p>
        
    	<p><a href="hotel.html"><img src="http://bytes.com/images/hotel_tag.png" alt="hotel" name="hotel_tag" width="97" height="27" border="0" id="hotel_tag" /></a></p>
        
    	<p><a href="guestbook.html"><img src="http://bytes.com/images/guestbook_tag.png" alt="guestbook" name="guestbook_tag" width="97" height="26" border="0" id="guestbook_tag" /></a></p>
        
    	<p><a href="riviera_maya.html"><img src="http://bytes.com/images/riviera_maya_tag.png" alt="riviera_maya" name="riviera_tag" width="99" height="26" border="0" id="riviera_tag" /></a></p>
        
    	<p><a href="rsvp.html"><img src="http://bytes.com/images/rsvp_tag.png" alt="rsvp" name="rsvp_tag" width="97" height="26" border="0" id="rsvp_tag" /></a></p>
        
    	<p><a href="questions.html"><img src="http://bytes.com/images/questions_tag.png" alt="questions" name="questions_tag" width="97" height="26" border="0" id="questions_tag" /></a></p>
        
    	<p><a href="index.html"><img src="http://bytes.com/images/welcome.png" alt="welcome" width="97" height="26" border="0" /></p>
    	<p><img src="http://bytes.com/images/plan_facts.png"  alt="" name="plan_facts" width="99" height="140" border="0" id="plan_facts" /></p>
        
  <!-- end #sidebar1 --></div>
  <div id="mainContent">
   <img src="http://bytes.com/images/sand.png" alt="sand" name="sand" width="642" height="561" border="0" id="sand" />
	<!-- end #mainContent --></div>
	<!-- This clearing element should immediately follow the #mainContent div in order to force the #container div to contain all child floats --><br class="clearfloat" />
 
<!-- end #container --></div>
</body>
</html>

i am using windows xp professional

[TheServant]

Don't have time right now to test this out, but have you thought about using the background CSS property for your header div? Really, you should be putting as many images in your CSS as you can as they are generally only downloaded once. If you use <img /> tags, they can be downloaded every page load. You might find that will solve your problem anyway.