Hi,I did the following test. Flight for about two hours and then landing check the fps (with fraps) 18 stable save the flight and then without close the FS9 i load again the same flight and now fps are 25. Why??RegardsTunka

Could be the autogen issue which is still present but much reduced with the FS9.1 patch.However it could be a number of other things - AI traffic and weather seems to change even if you load the exact same flight again - so it's possible there were less clouds before you reloaded or maybe less AI. Other than that there's always a number of things that cause computer programs to slow down over time and reloading the flight might have cleared some "junk" data.