During the last few weeks I've been tweaking, installing scenery, AFCAD files and aircraft, etc, to FS2004 on a new computer, and until today it has been virtually trouble free.Now the framerate drops to 1 when I try to move on or close to the ground. It happens with any aircraft, and at any airport. Slewing still works, but not good old taxiing, taking off or landing. As soon as the plane starts moving the framerate drops to 1 and the sim becomes unusable. But if I slew to altitude, and start flying from there, it works fine until I'm about 50 ft above the runway, then the framerate goes back to 1 again.Now, I must admit that I've done quite a lot of scenery installing and other tweaking the last few days, so finding the cause might not be that simple. The things I did right before it started stuttering:Today I installed the new Netherlands 2000 release, and the IFSD scenery of Irish airports. I deactivated both sceneries in the scenery.cfg, but the stuttering remains. And I find it hard to believe that a scenery would cause stuttering over the whole world...I moved over large amounts of AI traffic from another computer, but disabling that traffic doesn't have any influence on the stuttering.I also did some FS9.cfg edits, but I removed the FS9.cfg and let FS build a new one on startup, and the stuttering was still there.Last but not least (well, probably least!) I installed the FS Night Environment Upgrade (v. 2), but as the problem occurs regardless of the time of day I can't see how that can have anything to do with it.I didn't change any video card settings, and changing them now does nothing.I really am out of ideas...Martin767 fetishistIt's a lot like life and that's what's appealing

I believe this may be related to problems with Force-Feedback config... You can try to disable it and/or search the threads for a better answer...-John

>search the threads for a better answer...But yours was a good answer John! :-) It was the force feedback, but I'm slightly surprised since it has worked without problems for almost six years now!I'll have to dig a bit deeper into this now. Thanks for solving the mystery!Martin767 fetishistIt's a lot like life and that's what's appealing

Martin, AFAIK, you only need to disable the 'Ground Bumps' in the FFB settings. Hope this helps. Good luck and rgds Jaap

Thanks, I found out. But if I only disable "ground bumps" I still get a big framerate reduction, it goes from 25 fps to 9 fps if I have control surface forces enabled. So for the moment I've disabled the forces entirely.Martin767 fetishistIt's a lot like life and that's what's appealing