FSUIPC doesn't even touch the keyboard input unless you program them in FSUIPC. You must have something else going on there. I'm using TrackIR with FSUIPC 4.30 and it works fine. I was merely a bit peeved that something in the way TrackIR reads its keys stops me programming them on a Button instead, as my keyboard is usually rather out of reach, and the "re-centre" key seems to be needed quite frequently when it appears to lose its orientation. Not nice on approach! ;-)
Regards
Pete
You can change the key that you use to recenter to anything you like (within the TrackIR profiles). I usually change them to a joystick button, so I don't have to use the f12 key for centering