I've got a similar problem and after searching the forum here I haven't seen an answer (or one I understand anyway!
)
I've just gotten the Logitech Momo wheel and it works fine in other stuff but GP3 refuses to see it as having FF--the forcefeed back setting is greyed out and can't be changed. And as expected I don't get any effects.
Obviously others have at least gotten past that part -- what did I miss?
Any and all help appreciated!
Dick