hardware control doesn't show up in cubase 7.5.3

… and if i load an load project and add the inputs of the new interface (mr816), the hardware control shortly shows up - but when i try to click it to expand it in the mixer it just disappears…
don’t know what to do - getting frustrated… is the mr816 an old, unsupported product? it’s the only low latency, firewire product steinberg offers… am i better of sending it back and ordering one of the (more) current usb interfaces?
have to say - was a bit shocked to see that not even the online manual has been updated to the latest version of cubase… it’s stuck at version 4… dosen’t make me feel confident about the purchase…