You’re getting a weird version of the mobile layout because your browser is responding incorrectly to the media queries in the stylesheet.
The query is:
@media handheld and (max-width: 480px), screen and (max-device-width: 480px), screen and (max-width: 500px)
I notice that you are using a Software AG version of IE9. I don’t see the same when using a vanilla IE9 download so there must be some configuration in your corporate version that is causing this. I’ll do some research to see if this is a known problem with badged versions.
Are you able to try with a vanilla IE9 download?