I use FSX with FSUIPC4 to operate the controls for me.After a long VFR flight in a Cessna 172 - using AP either in NAV mode, or in GPS mode with a flight plan loaded - during my approach, after deactivating AP, I realize that rudder control no longer works (makes for an interesting landing). Once on the ground neither rudder nor differential brakes work (makes for interesting taxiing). I opened FSUIPC and the axis assignments/calibration seemed normal. When I exited FSUIPC and resumed FSX, the controls worked as they should!I use Saitek yoke/TQ and pedal/brake units.I can't blame FSUIPC4 because I also tried operating rudder and brakes using the keyboard NUM keys. That didn't work either. It appears that I can recover from this annoyance and land/taxi normally by opening, then closing FSUIPC shortly before beginning an approach but that's not really a fix.Any diagnostic suggestions gratefully received. MH

Are your sensitivity settings at max for the rudder and brakes functions in the Controls menu of FSX?

I've disabled FSX's axis control so nothing will interfere with FSUIPC's control. However, in the FSX Settings Controls window, on the Calibration tab, there are only sensitivity settings for ailerons, elevator, and rudder (and only the rudder malfunctions). There's nothing for diff brakes (where would I find that?). All three are set to zero. Am I looking in the wrong place? Since I have FSX settings disabled I don't know why these sensitivity settings would make a difference.

My suggestion prob won't help then. But there is a 'toe break' sensitivity setting in the 'advanced' control settings section.