I think your additional wrappers may be causing you issues.
I'd possibly go back to a basic 100% height layout and then add your content.
This works across all browsers including IE6.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head><title>100% Height CSS Layout</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css">
* {
padding: 0;
margin: 0;
}
html, body {
height: 100%;
}
#container {
min-height: 100%;
background-color: #CCC;
width: 75%;
margin: 0 auto;
}
* html #container {
height: 100%;
}</style>
</head>
<body>
<div id="container">
<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Quisque tempor. Nam in libero vel nisi accumsan euismod. Quisque quis neque. Donec condimentum, enim convallis vestibulum varius, quam mi accumsan diam, sollicitudin ultricies odio ante vitae purus. Etiam ultricies quam. Vestibulum turpis turpis, fermentum ut, accumsan quis, tempor at, ipsum. Nam felis elit, sollicitudin id, ultrices faucibus, fringilla vel, dui. Aliquam tincidunt iaculis eros. Sed in lorem. Nullam eu enim. Quisque tristique pretium diam. Fusce tempor sollicitudin ligula. Donec purus eros, mattis quis, mattis vestibulum, congue quis, felis. Nulla facilisi. Nam ultricies posuere justo. In feugiat.</p>
</div>
</body>
</html>