For the last few days I have been experiencing a strange FPS issue in FS2004. After about 10 minutes of flying, the framerate drops from 30fps to only 8-12fps for about two minutes. Then it goes back to normal. I noticed that my HDD is accessing a bunch of stuff during the framerate drops, but I have no idea what it is doing because I am not running any progams in the background except REX weather engine. I would appreciate any ideas that could help me solve this issue. Thanks.I have a NVIDIA GeForce 9600M with the latest driver (285.58).

Never mind, I figured it out. I had an old version of FSUIPC installed, and the communication between FSUIPC and REX Weather caused the FPS drops. I installed the newest version, and now everything works great.