I am using this chunk of jQuery/Javascript code on my site to open a popup window:
$('#change_photo_link').click(function(){
    $id = $('#id').attr('value');
    window.open("photo.upload.php?id=" + $id,"Upload Photo",
    "menubar=no,width=430,height=100,toolbar=no");
});
This code works on Firefox and Chrome.  It does not work on IE7 or IE8 (haven't tested IE6).
IE pops up an error on the line window.open.  Why?  The error that IE gives is "Invalid Argument" and that's all.