The YDP-131 manual is not very clear about it, but the only place where it mentions that data from the MIDI IN is played is in the section where it describes what happens when "Local Control" is off. So try changing the Local Control setting. Also check that the receive channel is set to ALL (which should be the default).
What Yamaha driver? As far as I can see, your USB/MIDI interface is not made by Yamaha, and the YDP-131 has no built-in USB. So there is no Yamaha device that would need a driver.