I tried to register the serialnumber for my oldfer Presonus 24.4.2 Ai, but I get a comment that it is already registered ? This is a mixer given to me from Luthmann in Norway in return for a 24.4.2 mixer there was a lot of problems with. Now Luthmann is "history" and no one can help me here in Norway, so please tell me what to do, all the best Foosen