- Did you turn the Yamaha keyboard "Local off" (if it has internal sounds, you may need to disconnect the "internal connection" between the keyboard and the sound electronics this way).
- Try to enable "low latency/low precision mode in the device output's right-click context menu.
- There have been complaints about issues with some (in particular older I think) M-Audio MIDISPORT and Uno interfaces on various hosts:
https://www.google.com/search?q=m-au...+dropped+notes
Some Uno interfaces are defective:
http://www.m-audio.com/index.php?do=...drivers&f=1262