SuzyUK - 9:46 am on Jul 5, 2011 (gmt 0)
It's displaying fine (IE8 Mode) for me locally too, but in IE7 standards when viewed via browser - this suggests, to me anyway, a previous site version or server level setting of IE7 standards. - (PS: I also checked that my "intranet" settings are the same as normal browsing, so it's not that)
I checked the Compat View list [msdn.microsoft.com] and this site's not on it, which suggests it's maybe the server level it's been set at, I think the best way to troubleshoot or "fix" the mode switching is probably to force IE8 (or edge) via the X-UA-Compatible header [msdn.microsoft.com] as it takes precedence over any previous setting.
<meta http-equiv="X-UA-Compatible" content="IE=edge">