Hi guys I just bought a mid 2012 macbook pro running OS 10.9.2. I have installed on it Logic Pro 9....unfortunately though my Yamaha PSR E403 keyboard is not showing up at all. The keyboard has a usb connection that I normally just connect straight into my laptop. I have gone into Audio Midi Setup in Applications > Utilities but the keyboard is not showing up. My M-Audio Midi keyboard shows up perfectly here. I have also tested the usb cables and they are working fine. I have also downloaded from the yamaha website the most recent USB - Midi driver. The most recent version (1.3.2) says that it is compatible with systems 10.5.x - 10.9.x I am not sure what the 'x' is supposed to mean? With my mac being 10.9.2 does that mean that they just don't have a driver that is up to date yet with Mavericks? The keyboard worked perfectly in conjunction with Logic 9 on my old Macbook. Any help would be very much appreciated!!!