I'm very light on the sticks in calibration. And it works perfectly. Flight after flight. Until one day it doesn't, and gives the "throttle stick" warning on startup. When I press down (not very hard either) you can feel something give way a little and everything is fine. It's like something is getting stuck in there.
I'm really not worried about it, and won't bother to fix it. I don't want to spoil it's magic mojo, since I seem to be the only guy on earth not experiencing the "full throttle at startup" issue when binding my quads to my 9x. In fact now when I bind to my 939 and x1 it doesn't even spin up. Binds perfectly, just like the stock tx. I don't know why, and I'm too noobish to try and figure it out.
As far as calibration, and what you guys are saying, if you are a bit bullish on the controls during calibration you'll notice because visually on the tx the stick position will actually go beyond the boundary box. Unfortunately you don't see this until after you're done calibrating, so it might take a few attempts to nail it. I did this right away, not because it's the right thing to do, but because I'm OCD like crazy and couldn't stand the two boxes not looking the same.