it's not really meant to be a hard puzzle, per se (that would be pointless and a waste of time). it's just intended not to be really really easy, and useful enough for us to say "this could be a good candidate" based on getting the correct answer.
Well the problem with this puzzle wasn't its level of difficulty, just that it was awkward to complete. It seemed more like a test of my Firebug abilities than anything else.
the fact that you're using firebug, know some basic concepts, can debug javascript and can formulate your own POST requests puts you above quite a few of the applicants we've seen.
