I find the following really strange, probably due to my ignorance: the following script works in FF, Safari and Opera, but not IE

Lovely IE simply destroys any session variables if there's an image with src=""

Here's the (incomplete) code:
Code:
session_start();
$path = $_SERVER['DOCUMENT_ROOT'].'/crs/cms/';

//get config file and db connect class
require_once('support/php/functions.php');

//check the validity of login
if (!$_SESSION['user']['logged']) {
	print("user not logged");
} else {
	print("user logged in");
	require_once('Addnews.class.php');
	
	$news = new Addnews($link, $dbname1);
	
	//get section name
	$news->get_section_name($section);

	
	//check if the form was submitted and what the action is
	//on first load
	if (!$_POST['todo']) {
		
		$datestring = date('Y-m-d');
		$titlestring = "Title";
		$articlestring = "";
		$sdatestring = date('Y-m-d');
		$stimestring = date('H:i');
		$edatestring = date('Y-m-d');
		$etimestring = date('H:i');
		
	} elseif($_POST['todo']=="preview") {
		$validation = validate_news_form($_POST);
		if ($validation=='') {
			//save the preview in the database and get the last id
			if (!$_SESSION['preview']['id']) {
				$last_id = $news->save_preview($_POST);
				$_SESSION['preview']['id'] = $last_id;
			} else {
				$news->update_preview($_POST, $_SESSION['preview']['id'], 'AWAITING');
			}
			
			$news->read_data($_SESSION['preview']['id']);
			
			$img1string = "../img/uploaded_images/small/".$news->result[0]['img1'];
			$img2string = "../img/uploaded_images/small/".$news->result[0]['img2'];
			$img3string = "../img/uploaded_images/small/".$news->result[0]['img3'];
			
			$datestring = ($news->result[0]['NewsDate'])?$news->result[0]['NewsDate']:date('Y-m-d');
			$titlestring = ($news->result[0]['title'])?$news->result[0]['title']:"Title";
			$articlestring = ($news->result[0]['article'])?$news->result[0]['article']:"";
			$sdatestring = ($news->result[0]['SDate'])?$news->result[0]['SDate']:date('Y-m-d');
			$stimestring = ($news->result[0]['STime'])?$news->result[0]['STime']:date('H:i');
			$edatestring = ($news->result[0]['EDate'])?$news->result[0]['EDate']:date('Y-m-d');
			$etimestring = ($news->result[0]['ETime'])?$news->result[0]['ETime']:date('H:i');
			
		}
	} elseif ($_POST['todo']=='submit') { 
		$validation = validate_news_form($_POST);
		if ($validation=='') {
			//save the preview
			$news->update_preview($_POST, $_SESSION['preview']['id'], 'ONLINE');
		
			//transfer the data to the public database and go to the newslist
			$news->transfer_preview($_SESSION['preview']['id'], $dbname2);

		}
	}
}


?>

<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<style type="text/css">
<!--
@import url("support/css/addnews_styles.css");
@import url("support/css/cms_gen_styles.css");
-->
</style>

<script language="JavaScript" type="text/javascript" src="support/js/tiny_mce/tiny_mce.js"></script>
<script language="JavaScript" type="text/javascript">
tinyMCE.init({
	mode : "textareas",
	theme : "advanced"
});

function submitForm(act) {
	document.forms['addnews'].todo.value = act;
	document.forms['addnews'].submit();
}

function getPic(num) {
	var picpicker = window.open("support/php/addpic.php?num=" + num,"Add_Picture","status=1,toolbar=1,location=1,menubar=1,resizable=1,scrollbars=1");
}
</script>

</head>

<body>

<!-- WRAPPER DIV START -->
<div id="wrapper">

	<!-- ========================================================================================================== -->
	<!-- BREAK DIV START -->
	<DIV style="height:7px">&nbsp;</DIV>
	<!-- BREAK DIV END -->
	<!-- ========================================================================================================== -->
	
	<!-- ========================================================================================================== -->
	<!-- BUTTONS DIV START -->
	<DIV style="height:91px">
		<div style="float:left; width:6px">&nbsp;</div>
		<!-- home button -->
		<div style="float:left; width:66px"><a href="home.php?section=<?= $section ?>"><img src="img/header/bttn-home.png"></a></div>
		<!-- =========== -->
		<div style="float:left; width:20px">&nbsp;</div>
		<!-- news button -->
		<div style="float:left; width:66px"><a href="newslist.php?section=<?= $section ?>&page=1"><img src="img/header/bttn-news.png"></a></div>
		<!-- =========== -->
		<div style="float:left; width:21px">&nbsp;</div>
		<!-- emails button -->
		<div style="float:left; width:66px"><a href="emaillist.php?section=<?= $section ?>&page=1"><img src="img/header/bttn-emails.png"></a></div>
		<!-- =========== -->
		<div style="float:left; width:22px">&nbsp;</div>
		<!-- photos button -->
		<div style="float:left; width:66px"><a href="gallerylist.php?section=<?= $section ?>&page=1"><img src="img/header/bttn-photos.png"></a></div>
		<!-- =========== -->
		<div style="float:left; width:23px">&nbsp;</div>
		<!-- results button -->
		<div style="float:left; width:66px"><a href="resultlist.php?section=<?= $section ?>&page=1"><img src="img/header/bttn-results.png"></a></div>
		<!-- =========== -->
		<div style="float:left; width:22px">&nbsp;</div>
		<!-- contacts button -->
		<div style="float:left; width:66px"><a href="contactlist.php?section=<?= $section ?>&page=1"><img src="img/header/bttn-contacts.png"></a></div>
		<!-- =========== -->
		<div style="float:left; width:26px">&nbsp;</div>
		<!-- vertical line -->
		<div style="float:left; width:10px"><img src="img/header/vert-line.png"></div>
		<!-- =========== -->
		<!-- CMS Logo -->
		<div>
			<div style="height:71px">
				<div style="float:left; width:208px"><img src="img/header/cms.png"></div>
				<div><img src="img/header/crs.png" width="190"></div>
			</div>
			<div id="section_label">editing <?= $news->section_name ?> section</div>
		</div>
		<!-- ======== -->
	</DIV>
	<!-- BUTTONS DIV END -->
	<!-- ========================================================================================================== -->
	
	<!-- ========================================================================================================== -->
	<!-- BREAK DIV START -->
	<DIV style="height:44px">&nbsp;</DIV>
	<!-- BREAK DIV END -->
	<!-- ========================================================================================================== -->
	
	<!-- ========================================================================================================== -->
	<!-- LOGO DIV START -->
	<DIV style="height:95px">
		<div style="float:left; width:6px">&nbsp;</div>
		<!-- NEWS LOGO -->
		<div style="float:left; width:208px"><img src="img/newslist/news.png"></div>
		<!-- ========= -->
		<div style="float:left; width:482px">&nbsp;</div>
		<!-- ADD NEWS -->
		<div style="float:left"><a href="newslist.php?section=<?= $section ?>&page=1"><img src="img/addnews/bttn-cancel.png"></a></div>
		<div style="float:left; width:17px">&nbsp;</div>
		<div style="float:left"><img src="img/addnews/bttn-preview.png" onClick="submitForm('preview')" onMouseOver="this.style.cursor='pointer'"></div>
		<div style="float:left; width:16px">&nbsp;</div>
		<div><img src="img/addnews/bttn-submit.png" onClick="submitForm('submit')" onMouseOver="this.style.cursor='pointer'"></div>
		<!-- ======== -->
	</DIV>
	<!-- LOGO DIV END -->
	<!-- ========================================================================================================== -->
    
    <!-- ========================================================================================================== -->
	<!-- BREAK DIV START -->
	<DIV style="height:40px">&nbsp;</DIV>
	<!-- BREAK DIV END -->
	<!-- ========================================================================================================== -->
	
	<!-- ========================================================================================================== -->
	<!-- TITLE DIV START -->
	<DIV style="height:20px; font-size:20px">Add News <span id="error_message" style="font-weight:bold; color:#FF0000"><?= $validation ?></span></DIV>
	<!-- TITLE DIV END -->
	<!-- ========================================================================================================== -->
	
	<!-- ========================================================================================================== -->
	<!-- BREAK DIV START -->
	<DIV style="height:8px">&nbsp;</DIV>
	<!-- BREAK DIV END -->
	<!-- ========================================================================================================== -->
    
    <!-- ========================================================================================================== -->
	<!-- FORM DIV START -->
	<DIV>
		<form name="addnews" method="post" action="<?php print(htmlentities($_SERVER['PHP_SELF']).'?&section='.$section); ?>">
			<input type="hidden" name="todo" id="todo" value="nothing" />
            <table border="0" cellspacing="0" cellpadding="0" width="950">
            	<tr> 
          <td width="105" height="24" valign="top"><input name="txtDate" type="text" class="login_box" id="txtDate" value="<?= $datestring ?>" size="10"></td>
          <td colspan="17" valign="top"><input name="txtTitle" type="text" class="login_box" id="txtTitle" value="<?= $titlestring ?>" style="width:783px" onClick="this.value=''"></td>
        </tr>
        <tr> 
          <td height="10"></td>
          <td width="21"></td>
          <td width="34"></td>
          <td width="15"></td>
          <td width="34"></td>
          <td width="75"></td>
          <td width="7"></td>
          <td width="34"></td>
          <td width="9"></td>
          <td width="25"></td>
          <td width="89"></td>
          <td width="7"></td>
          <td width="34"></td>
          <td width="84"></td>
          <td width="67"></td>
          <td width="88"></td>
          <td width="32"></td>
          <td width="190"></td>
        </tr>
        <tr> 
          <td height="352" colspan="18" valign="top"><textarea name="txtArticle" class="login_box" id="txtArticle" style="width:925px; height:348px"><?= $articlestring ?></textarea></td>
        </tr>
        <tr> 
          <td height="19">&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
        </tr>
        <tr> 
          <td colspan="3" rowspan="4" valign="top" style="background-color:#FAEBDE"><img src="<?= $img1string ?>" width="159" height="99" id="pic1">
          	
        </tr>
            </table>
    	</form>
	</DIV>
	<!-- FORM DIV END -->
	<!-- ========================================================================================================== -->
</div>
<!-- WRAPPER DIV END -->


</body>
</html>
The element in question is the image with id=pic1.
When the src of this image is blank, IE destroys all session variables when the page is re-loaded. If I put some src="adsf.jpg", it all works nicely.

What's the problem here?