Black screen after XBMC exit.

I have the most recent release of Raspbian Wheezy running on my RPi. I installed XBMC following these instructions.
The only other thing I have installed is Midnight Commander so it's a pretty fresh install.

When I exit XBMC via the GUI I get a black screen which prevents all user interaction. I can't change my terminal using Ctrl+Alt+Fx but I can SSH through to the RPi and restart it.

What is causing this and more importantly, how can I fix this problem?

I would appreciate your help on this.

P.S. I have created another thread with a different problem I am having with XBMC.