The first image is the result of two iterations (that is, only the direct lighting is shot) the second is after 10 or so. Anyway, enough that the error was pretty small, although I don't remember what it was.
Here's a kinda fun scene, which I developed while working on my final project. There is a bright blue emitter outside the "window" which lights up the floor under the table. Note also the blue light reflected off the table top onto the left wall.
