I seem to remember having a problem like this back in the day.
Try clearing any link in MobileSheets, and then re-linking the registration, making sure that there is NO registration actually selected. To paraphrase, load the Registration, but BEFORE selecting REG 1, 2, or whatever, link it.
That should do it for Registrations. I don't think you can link styles the same way though.
I also found that 99% of the time, I'm choosing music via Mobilesheets, and don't ever use the Genos --> Mobilesheets link.
Adam Parker