HI TOM,
I don't use a USB hub. The computer has 4 powered usb ports and I have tried all 4 even thought the other periphials plugged into them work fine as did the KN7000 for the last couple of years.
I just sent an in depth e letter to Yamaha support Steve Deming to see what they can tell me. I sent both you and Scott a copy.
Scott is sick so may not hear back from him right away.
Thanks,
Bebop