It's a key binding issue.
Find an empty server and figure it out.
I don't remember exactly what I had to change but I remember having to change some bindings to get the joystick on my G13 to move it.
That messed me up in other stuff...so not worth it to me.
EDIT...I think I actually had to assign the joystick to WASD...You'd need something like Motioninjoy to do that and then you have to redo ALL your movement bindings to WASD and use Motioninjoy 100% of the time.
The thing is seriously not worth the effort. Use a M/KB or give it up.