This version (0.4) now works with everything I have been able to throw at it. 
I have reworked the timing section so that it is tighter and more accurate in keeping the music to time. There were also serious logical errors in the processing of MIDI run on messages that caused the some files to play badly or not at all (see my first post).
I think there is a bit of tidy up to do and then it can be released as v1.