Just got FSUIPC today and it seems to not exist when I use FlyInside.
I set up all the controls on a regular (non-FI) session. When I started the FlyInside session, none of my FSUIPC mappings worked. I looked at the monitor looking for the "Addons" menu option, but it was gone.
I verified it again: flatland startup = FSUIPC; FlyInside startup = no FSUIPC.
Ideas?