Piano Booster is a very useful program but I have tried three different MIDI controllers and the staff display in Piano Booster displays MIDI C3 as middle C not MIDI C4 as it should be. This places notes in the music that belong in the treble cleff in the bass cleff when trying to play along with music made for standard MIDI.
http://en.wikipedia.org/wiki/C_(musical_note)
Perhaps a setting for middle C couild be added to the MIDI preferences to accomodate different keyboards with different numbers of octaves. It is strange nobody else has mentioned this. It could be me but three different controllers sending MIDI C4 place it an octave too high in the Piano Booster Staff Display.