I have a P4 2.8GhzHT 1024Mb RAM and a Radeon 9800Pro 128Mb. I have also installed the latest FS patch from the MS site.I discovered that my CPU is only running FS9.exe at about 50-55%. I thought that was normal but according to other users I have spoken to it should run at about 100%. I checked the Affinity option and both CPU 0+1 are checked. Does anybody has any idea how I could get my FS9.exe to run at 100% speed? Could it be that I am experiencing lower FPS due to this 'problem'?!

IIRC that situation is normal with HT enabled. Your PC only really has 1 cpu even though hyperthreading simulates the use of two, so 50% processor usage is accurate (and shouldn't be a problem)If you want more detailed info, just do a search on "hyperthreading" and you will find enough reading material to fill your day :)