I played around with it once.
It worked once....it knew a show a repeat one week, and it showed it as black with the no record symbol on it.
But, later I missed a new episode, because it decided not to record it. Don't know what TVGuide had for the show, but all my other TV listings clearly had it as a first run (fortunately...I wasn't into trusting the DVR yet...so I have recordings duplicated on my ReplayTV....)
So, now I don't use the first run feature.....
You may be a dreamer, but I'm The Dreamer, the definite article you might say!