First thing is to 'work' the pot, which can remove any dust/debris in the part. To do this, simply turn the pot back and forth through it's full rotation for a minute or so.
Connect the synth to MIDI Monitor or MIDI Ox, then see if you still get errant output (make sure all other MIDI applications are closed).
If you still have trouble, send us an email and we can help you out with the next steps. support@sequntial.com.