I have two FS9 aircraft that I've been flying in FSX now for thepast week or so. The planes in question are the FSDZigns L-049AConnie and Rick Piper's HS-748. Most of the time I can complete flights with no problems butoccasionally, usually after about 1 hour of flight time, FSX seemsto "lose focus" for lack of a better term. What happens is thatI can no longer control the engines ( throttle/prop/mixture )or the flight controls with my stick/throttle or with the mouseby clicking and dragging.I can still change throttle/pitch/mixture with the appropriatekeyboard commands. Using the "Aircraft Reload" command in flight does not correct the problem.Last night in the Connie I was on approach to EPWA and knewthe engine controls were gone so was controlling via keyboard.I had a good lineup on the runway using autopilot in approach mode.However, as soon as I switched off the autopilot 1 mile fromtouchdown I found that the joystick was inop. It was messy :(Other FSX vs FS9 related problems I have noticed is with enginestart. Both the Connie and HS-748 have controls/procedures forstarting the engines but these do not work properly in FSX.Autostart appears to work, most of the time, unless I try tomanually start the engine, then autostart may or may not work.I have also noticed this problem with FSX default aircraft...Beach Baron,for one. My "default" aircraft in my saved default flight is theConnie, cold and dark. This may be contributing to the startproblem but I don't think it has any bearing on the in-flight loss of control.Any insight out there? Paul

I think I may have discovered the problem. The previous versionof FSUIPC4 apparently had a problem if the connection to theinternet was unavailable. This caused problems with the stick/ruddercontrols.I have ZoneAlarm as my firewall and during FSX flights I wasnoticing continous 'net activity...not just during the "real worldweather updates" every 15 minutes.I would sometimes "lock" net access in ZA and then renenable it.The continous activity ceased. I didn't think much about it other than wondering WHY MS FSX was accessing the net continously.Apparenetly what I waas seeing was some sort of FSUIPC activity,although I'm still in the dark as to what/why or where it is trying to communicate. In any case, the most recent version of FSUIPC4 supposedly solves the control issue and hopefully my problems.We shall see. Paul