This issue seems very similar to the one outlined here, however none of the steps suggested in that topic have helped me. I have documented everything I've tried in more details there.

The only thing that makes it work again is changing the compilation debug switch to true in the web.config

All permissions are correct

The site works fine on my local dev environment but on the server it's broken

I can't see anything wrong in firebug Network panel, as per screenshot below:

There are a couple of javascript errors:

Is that likely to bring the whole backend down.  And why only on the server?