Don’t know who might be reading this now, but I have had the same problem - working fine as interface but Zoom not listed under Mackie Control. I’ve only had the Zoom for 6 months or so and Cubase for less and I don’t get enough time to really learn them. When I first got the Cubase I set the Zoom as a controller by just following the manual instructions - no problem. Now, months later when I want to use it seriously I can’t seem to do it. I will try the advice mentioned here (thanks by the way, I’m sure it will do the trick) and post again when I’ve hopefully got it working, as a reassurance for any one else having the same problem.