Ok, so I uninstalled my Maple Virtual Midi Port, uninstalled GPO STudio, reinstalled GPO Studio and now in Sonar I can see the GPO STudio Midi Ports under midi devices. HOWEVER, in the bundled Overture, I do NOT see GPO Studio\'s ports. So, either GPO Studio is not registering its midi ports properly (and Sonar is more forgiving) or Overture is to blame. Subsequently, I was able to reinstall the Maple Virtual Midi Ports again, so in Sonar, I have GPO 1-8, Maple 1-4, A800 (Audigy) & Delta. Unfortunately, in Overture GPO STudio still doesnt show (as expected).