hi Craig, I think I can help you
my Griffin was staying there unused and now it does best work with FCP7
– you should download the driver from Griffin https://www.griffintechnology.com/support/powermate/
the 2.1 version, works best, even on Snow
– after installation you shoul see the Powermate icon on your taskbar
– on the left of the setting window you choose your application: FCP
– on the right you set the action for the movements, for example turn right: scroll right. You can even set the speed of scrolling. That is what someone needs. Toghether with a Kensington expert mouse, for color correction, and a full programmable Ergodex keyboard, editing becomes an ergonomic pleasure.Tom