[Plugin: W3 Total Cache] website looks all wonky on ie & firefox when minify is enabled

ecoventi.co.uk is my website which was working okay yesterday but today it looks all wrong with minify enabled ,different colors content all over the place on ie & firefox but on chrome everthing is okay,now when i disallow minify it is okay on all browsers

please help

http://wordpress.org/extend/plugins/w3-total-cache/