OK, I fixed it, as I didn't realize that the flight controller assignments weren't automatically set! Jeez, I about pulled my hair out, since FS2 is the only one that I have (FSX, XP11, P3D) that does this. I had to manually assign the x, y, and z axes to the controllers in the settings in FS2.
Is this normal behavior, or is FS2 "supposed" to automatically assign these to the plugged in flight controller? It seems like it should be more intuitive than this...