Midi ghost notes on Master bus

Not sure how this happened but I have been using Qtractor and Renoise together and sending song position pointers from Renoise to Qtractor. Anyway the problem I now have is that even after a new install of Qtractor when it is run on its own with a new file the Master midi bus always has output. There are no midi files loaded. I insert a new empty midi clip and hit play. in the mixer the Master bus is playing midi notes. Using midisnoop these notes are Note on Note offs channel 10.