in xorg.conf works with the few joysticks I tried. Just don't add anything else for the joystick and keep the xorg.conf that came with Intrepid (It should be almost empty). However it might mess up other devices, just keep that in mind (but if it works for you, using it is better than trying to play x-plane with a keyboard ;) ).
And indeed (I forgot to add this to my previous post)
Section "ServerFlags"
Option "AutoAddDevices" "False"
EndSection
in xorg.conf works with the few joysticks I tried. Just don't add anything else for the joystick and keep the xorg.conf that came with Intrepid (It should be almost empty). However it might mess up other devices, just keep that in mind (but if it works for you, using it is better than trying to play x-plane with a keyboard ;) ).