By default IE8 forces intranet websites into compatibility mode. I tried changing the meta header to IE8, but it doesn\'t acknowledge the meta header and just uses the brows
For anyone else reading this looking to disable this via GPO for all users, this is the setting:
Computer Configuration/Administrative Templates/Windows Components/Internet Explorer/Compatibility View/Turn on Internet Explorer Standards Mode for Local Intranet
although the web.config edit fixed it for me.