Help with controls

My hardware as follows:AMD 2500, ABIT NF7 mobo, 1024MB PC3200 DDR RAM, 128MB Radeon 9800 Pro (Cat 5.13) WinXP SP2, Thrustmaster Fox 2 Pro joystick, TrackIR 3 Pro.I'm finding that with smaller aircraft in FS2004, when I'm taxiing, my Cessna 152 yaws left like its supposed to but when I rudder right to compensate even just a little bit, I overcompensate and end up fish-tailing down the taxiway. What settings in my controller config should I make to fix this? Is this a "small aircraft" issue? I'm guessing I should make my null zone as small as possible and increase the other slider. Your help is appreciated.Also, I guess this is a scenery issue, but I've downloaded some of the free scenery but, even though I move up the folder in the scenery settings library, the scenery doesn't show up differently than the default scenery. Am I missing something?Thanks for all your help from a NOOB.