Uhhh, I don't know how to say this, but all of a sudden, without doing anything, hildon-desktop crashed very strangely (there were UI elements all over the screen), and when it "recovered", there was a window present.

It looks like the carman "C" is my new background .

A reboot should solve this, but has anyone else experienced this problem with the most recent update?

I've had this a couple of times. a reboot fixes it with no other affects. There is probably a process which can be killed, but I just quickly restart.