Dear Team,I have a problem with my 747 FS9. I have not flown for sometimes now, recently I decided to give it ago. I loaded my 747 everything went smooth, set FMC like normal. During take off everything was OK. After reaching 10000 feet I turned on my LNAV and VNAV and monitor everyting. Then I decided to minimized FS9 and do some work on Vista. 1 minutes later I decided to check the climb and to my surprise the autopilot went crazy. LNAV and VNAV light was working but my Auto throttle was switch off, I need to activate it again by pressing VNAV. Not only that the aircraft itself went decent rapidly (sometimes with -5000 FPM). Then after several minutes the aircraft behave as normal again. Basically I could not minimized FS9. This problem occurred with/ without time compression. I have uninstalled FS9 and all its add-on. Delete all the registry then installed just FS9 with update 9.1, PMDG 747 V1.1 with no sound update. All those efforts gave ZERO result, autopilot still giving problem when FS9 is minimized.It is rather strange coz the last time I used FS9.1 with all its add-on with vista, my PMDG 747 gave no problem at all. I tried to do some research on AVSIM and googled it but couldn't find any solution.I would appreciate it if anyone could give some light for this.RegardsHendrik Herryjanto

Hendrik,Doesn't minimizing FS9 defeat the whole purpose of why we fly this simulator? ;-)mode>Cheers,

Yeah well its true. But sometime I don't have all the time I need. So any pointer on this.

>So any pointer on this.No, non other than the work-around not to minimize but keep it in the background. I think this is what can happen as the automatic flight system is built completely outside of FS standards to make it behave as IRL.Hope it helps,

Hmnnn.. Today I just tried to fly PMDG 737 and everything went smoothly with minimized FS9.The thing that I don't understand is that why it happens now not a long time ago. I just don't get it, I don't remember changing or adding anything new. Do you think it has to do with FSUIPC settings? I have registered version. Would you mind sharing your FSUIPC settings?BTW: all the test flight is done with clear weather settings from FS9.

I always found the Queen to respond to lost of focus (changing active window) with a "partial" disconnect of VNAV. On return of focus, the VNAV is no longer working the way it should although the annunciators are nominal. Just press VNAV (once or twice) and everything is back to normal, in my experience. This doesn't seem to happen to the 737NG.

Yes Dan you are correct. However the problem is not just the partial VNAV but also the decent rate of the queen. From all the test flight I have done, most of the time I ended up in crash (nose down).So, is this common problem then?