Ok, I seem to have found where the problem lies. The image does center properly on the link provided because it is inside an iframe. Inside a normal page flow the image will display at the top of it's enclosing container.
As table et display: table-cell are broken in IE the fix requires a minimal enclosing table:
<html>
<head>
<style type="text/css">
#content { border:solid 1px;}
img{ max-width:400px;max-height:400px;margin:auto;}
#page-table {
height: 400px;
width: 400px;
border-collapse: collapse;
text-align: center;
border:solid 1px;
}
#page-td {
height: 100%;
padding: 0;
vertical-align: middle;
}
div#content2{
border:solid 1px;
width: 400px;
height: 400px;
/*line-height: 400px;*/
text-align: center;
display: table-cell;
vertical-align: middle;
}
img#image2 {
max-width:400px;
max-height:400px;
vertical-align: middle;
}
div#enclosingdiv2 {
border:solid 1px;
}
</style>
</head>
<body>
With table:
<table id="page-table"><tr><td id="page-td">
<div id="content">
<img src="http://lorempixum.com/250/250/abstract">
</div>
</td></tr></table>
Without:
<div id="content2">
<div id="enclosingdiv2">
<img id="image2" src="http://lorempixum.com/250/250/abstract">
<div>
</div>
</body>
</html>