Hmm, interesting answer. I like that one.
Definately something sneaky has to be going on here. There are 6 possibilities for wiring the lights, and simply turning on 1 or 2 still leaves you with 1 bit of information left unknown. That is, two lights and two switches unknown leaving 2 possibilities. (And turning on 0 or 3 gives you no info).
For this to be solvable, there definately has to be a hidden information source such as the heat of a lightbulb.
Hmm, what about power efficient lights?