Q:

IE7 and fixed divs problem

Background
I need to do a rather complex layout for a client, using fixed DIV. Everything is fine in IE8, FF3 and Chrome, but IE7 mangles all the thing  
Edit: The fixed DIVs are a must, only the content DIV must scroll (That is the spec, sorry)
HTML and CSS code
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /><title>
    test
</title>

    <!--[if lt IE 8]>

    <![endif]--> 

    <!--[if lt IE 7]>

    <![endif]--> 

</head>

<body style="margin: 10px;">
<div id="wrapper" style="width: 960px; margin: 0 auto; position: relative;  border: 1px solid red; overflow: hidden;">

    <div id="header" style="position: fixed; width: 185px;  height: 600px;  top: 10px;  border: 1px solid blue;">
      header
    </div>

    <div id="content" style="width: 680px; float: left; background: white; margin-left: 185px;  min-height: 600px;  border: 1px solid lime;">
        content
    </div>

    <div id="rightcolumn" style="position: fixed; top: 10px; width: 90px; margin-left: 865px;   height: 600px;border: 1px solid maroon;">
        right
    </div>

</div> 

</body>
</html>

Width IE8, FF3 and Chrome
IE8, FF3 and Chrome http://img39.imageshack.us/img39/406/firefoxkpd.jpg
Width IE7
IE7 http://img23.imageshack.us/img23/1315/ie7l.jpg
Notes
I'm not so worried about IE6 because I know it does not support Fixed elements, but if you know how to fix it, great!
Questions

What should I know about IE7 bugs to fix the problem?
How can I reference the left in the header columns relatively to the wrapper
Why the header column goes the the right and the right column disappears? 

A:

Found a fix!! Strange enough floating the content to right fixes it!
Do I earn a cookie?
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /><title>
    test
</title>

    <!--[if lt IE 8]>

    <![endif]--> 

    <!--[if lt IE 7]>

    <![endif]--> 

</head>

<body style="margin: 10px;">
<div id="wrapper" style="width: 960px; margin: 0 auto; position: relative;  border: 1px solid red; overflow: hidden;">

    <div id="header" style="position: fixed; width: 185px; height: 600px;   top: 10px; border: 1px solid blue;">
      header
    </div>

    <div id="content" style="float: right; width: 680px; margin-right: 90px; height: 600px; border: 1px solid lime;">
        content
    </div>    

    <div id="rightcolumn" style="position: fixed; top: 10px; width: 90px; margin-left: 865px;   height: 600px;border: 1px solid maroon;">
        right
    </div>

</div> 

</body>
</html>

