Cisco ISE: Change of Authorization (CoA) not working

We had a wireless security implementation at a customer site which consisted of the following components:

The setup included a wireless lan for guest access by using the Cisco ISE guest portal functionality.

We started by configuring the WLC's and ISE environment and having done that everything worked as a charm. A couple of days later we we were not able to connect to the wireless network.
The error reported in the ISE Authentications overview was:

Dynamic Authorization Failed : 11213 No responds received from Network Access Device

MacBook Wireless Borked Again, Still, etc.

A while back I had regular issues with the wireless adapter on my MacBook after I had upgraded to OSX Mountain Lion, but after the removal of Little Snitch (I still ran the beta version) it seemed that times were a changing... Seemed that is.

This morning I was fiddling about with my photo website, and needed to see the results in several different browsers. One of them being Google Chrome.
Trying to launch the Chrome app, it crashed immediately. Reopening didn't help. So I tried to download a newer version, since I hadn't updated mine since the upgrade to Mountain Lion. The result; It still crashed. Even after removing all Chrome (and Google) references on the disk, it still crashed.

So, it became time to consult the book of knowledge, and see what the Internets had to say about my little ordeal.

Unable To Turn On Wireless In OS X Mountain Lion

Last night I was minding my own business on the couch, when the wireless connection on my MacBook (UniBody) decided to call it a day. According to the symptoms (no bars visible in the WiFi icon in the menu bar, no visible wireless networks in the vicinity), the WiFi adapter was turned off. Turning the WiFi back on was not possible though.