Problem: A CC2 (breath controller) message with a value of 127 appears to be ignored by GPO if the previous CC2 message had a value of 0 (and, depending on the instrument, sometimes 1 or 2).
When playing an X-Custom instrument with a wind controller, this results in sforzando notes following a rest or tongued break starting more quietly than expected (if the assignable slider for an X-Custom instrument is set to 99% or lower), or completely silently (if the slider is at 100%). Once another CC2 message is received, the instrument jumps up in volume to the appropriate level.
Steps to reproduce:
1) Load this MIDI file into any GPO-compatible sequencer.
2) Create an instance of GPO and load a treble X-Custom instrument (trumpet, flute, violin, etc.) into slot #1, with the assignable slider set to CC2, at 75%.
3) Assign the MIDI track to channel 1 of the GPO instance and play the project.
4) Set the assignable slider to 100% and play the project again (it helps if your sequencer can show where the CC2 messages and note beginnings are).
Edit: This happens for me in SONAR (Windows), but it also happens if I set WinAmp to play MIDI files to GPO Studio.