IE 8 malfunction

This website http://bgen.org.uk.gridhosted.co.uk is all OK except it won’t work in Internet Explorer 8. I have set the theme options scripts On, and I have adjusted the header.php but still no joy.

Anyone got any ideas? (Please don’t say ‘update your browser’: this is for a significant portion of the site audience (about 8%) that still use IE8 and work from government offices where they can’t update their software. As things stand, there is nothing we can do right now about this)

Thanks