Try forcing the issue with the following meta tag.
<!-- force IE8+ into standards mode -->
<meta http-equiv="X-UA-Compatible" content="IE=edge">
It should be the first meta tag in he page.
e.g.
<!DOCTYPE HTML>
<html>
<head>
<!-- force IE8+ into standards mode -->
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta charset="utf-8">
<title></title>
etc...