#1 : I fully realize this thread is years old.
#2: I post here because this issue still exists.
I am running the latest version of the game obtained via Steam. I started X3:T3 in December 2013. I did not have this issue in X3:T3 with my 45 day game (as reported by Player Status).
In X3:AP, my game had become unplayable in any real-time sense of the word. Merely moving the mouse was laggy, much less attempting combat of any kind.
After research, I created a Director folder in x3 terran conflict/addon, and placed this file in it:
http://dl.dropboxusercontent.com/u/2735 ... .xml.fixer
Upon reloading the save game the difference was immediately apparent, the game is back to smooth as glass. I saved, exited, removed the file, and reloaded, and still smooth as glass. So something in the Mission Director is still broken over time.
My system: i7-3770 @ 3.4Ghz, 16GB ram, Win7 64 bit, Nvidia GTX 770.