I recently installed MixPad on my Macbook pro to playback MIDI files on my Yamaha HSQ300 via a midi-USB adapter. It's strange that some MIDI files are fine but some others are not (e.g. http://www.piano-midi.de/midis/beethoven/pathetique_3_format0.mid) The problem manifests as some notes are not played and some keys are not released. However, when I tried the internal sequencer, the MIDI files are OK. Does anyone know what's wrong?