My new system is less than two months old and this is the first time that I have seen this, it does this with both the default FSX AI and MyTrafficX AI.It is only when the AI is in the air, while on the ground the AI does not do it, even when they are moving along a taxi path.The best way that I can think of to describe it is for you to put your hand in front of your face and move it left to right to left to right and keep doing it, do this at a moderate pace, this is what the AI planes look like if I am flying beside them. They vibrate forwards, backwards, forward, etc. all the while continually moving forward on their flight plan. They do not vibrate left or right, only front to back and they follow the flight plan in a straight line.I tried to take a screen shot, but the vibration is slow enough that it does not show up in a screen shot.Does anyone have any ideas on how to get this to stop, I really would rather not go through the whole uninstall/reinstall routine. I have had FSX on two other PC's and have never had this happen before. I just noticed this last week on this PC and I can not say for sure if it just started or if it has been like this since I installed FSX on this PC in September.My specs are in my signature, I have this set up per NickN's Win7/FSX guide, the drives are defragged and everything. This is the only issue, no stutters or anything, just this vibrating AI. I doubt that it matters, but my FPS is over 30 anywhere I go and it spikes into the 100's, plus like I said, no stutters, the sim is smooth as silk, except for this AI problem. Even when I am flying next to the AI and it is vibrating, the ground, sky, water, everything else is rock solid, no blurries or anything.Thanks for any help or ideas!Rod

Actually I have learned that it is called the shimmy effect and it is caused by using a frame rate higher than FSX can compute and draw the AI. I locked my FPS to 30 and all is well!

I know what you're getting at but to be sure can make a short video the next time that happens if possible.:(