Recently I have noticed some addon aircraft particularly the Dreamfleet 727 veer off the runway when rolling down the runway to takeoff despite joystick being in neutral position. Default aircraft are fine.Once the DF 727 has taken off it veers to the right despite the joystick being in a straight position. This problem has persisted despite using different joysticks. any advice appreciated

you might try a different runway and or take off into the wind. it does help. i had the same problem awhile back and noticed if i did the above it helped a good bit. william

Actually, I've had problems taxiing and taking-off/landing - i.e. ground maneuvering. I found the fix that my CH flightyoke has to be setup a certain way to make sure there is a slight "dead zone" of 1% and the CENTER checkbox selected so that the rudder and rudder trim remain centered. Also, I had to calibrate my yoke and pedals recently.It's possible that the default aircraft don't respond the same way to mis-calibrated joystick. Perhaps you have similar issue - verify how your joystick sensitivies are setup and if there is dead zone adjustment as well as a center option. It's also possible to edit the AIRCRAFT.CFG files for the add-ons but only changing the lines for "RUDDER RESPONSIVENESS" and "RUDDER TRIM RESPONSIVENESS" - reduce them to, say 0.50 or half the value shown but I'm not sure if this will fix your problem.Have you chnaged any settings in FS2004 lately like the GYRO EFFECT?Hope this helps.John