yep, i mentioned that in my post, if that top gear comes up when you try to pull the lower rotor up, its binding a little. definitely dont file the notch away, all that needs to be done is to widen the gap in the notch a little bit so when the lower rotor and upper gear connect, its not such a tight squeeze between the two. still not sure why that causes such a binding problem, but i had the same problem. after filing the notch a little wider, it was better, i just used a fingernail file (they're life savers!).

nick