I have a Casio CTK-4000 and when I plug it into my computer (Windows 7) via MIDI to USB cable and turn on Mixcraft program my keyboad doesn't produce any sound (it doesn't control any virtual instruments).Ive done exactly what so many forums/manual/youtube vids have said and it just wont make a sound. THe program recogonizes a change in MIDI devices and it shows the casio keyboard under preferences so im not sure. Ive tried so many different things but can't get it to work. It used to work fine when I did this in Mixcraft 5, the keyboard seems to be in good shape idk whats going wrong this time around.