Hi,
When I use Firebug on your site, on the network tab in Firebug I can see it is returning a bunch of 500 error status codes for images and javascript.
Did you use the Web.config file that shipped in version 2.3.8.5 or did you keep your old one?
Something is wrong on the server configuration for static files, I would look in Web.config if you have a section for <staticContent try removing it completely.
Hope that helps,
Joe