So this happened:
http://imageshack.us/photo/my-images/9/screenshot20111219at448.png/
Image is pretty self explanatory. Has only ever happened twice to me - both times it started when I entered this room:
http://imageshack.us/photo/my-images/51/screenshot20111219at427.png/
I'll start posting more screenshots - this has become an annoyingly common problem