IE Stylesheets being ignored - only on production server though Production server - http://speysideleisure.com

Dev server - http://superallan.com/dev/speyside/

On IE the Dev site is referencing the css properly but the Production site isn't. The Prod is hosted on different servers with a different host - all the files are the same though. The only thing is that I noticed the problems once I'd uploaded it to the Prod server so then I made the changes. I've cleared the Cache a million times but that's the extent of my knowledge in how to solve it. The Dev site changed pretty much instantly.

Is it a setting somewhere on the Prod server?

Cheers for any help - it's appreciated.
IE chokes if you have more than 31 stylesheets, which most Drupal sites do if you create a zen subtheme. Turn on CSS aggregation in your performance settings to fix that.

There are potential (temporary or easily fixable) problems associated with migrating a Drupal site from http://example.com/dev/ to http://example2.com/ that you can avoid completely if you develop on a subdomain, ie. moving http://dev.example.com to http://example.com

check your database and theme files for paths starting with "dev/" and give your .htaccess files the once-over.