Sometimes I encounter this issue- I've got one MIDI track with a VST (Maschine, in this case) that is not record-armed. I load up another track with a synth that I'm playing on the push. As I am playing in my synth track, one sound from Maschine (a drum sample pitched across the keys) is also sounding in the background.
So basically, my MIDI playing is triggering multiple tracks at once. I thought that only the record-armed track would be triggered, as this is how it normally works.
Any thoughts??