PlanetZ forums - scopeusers.com

some master keyboards (like roland a33) sending midi clock by default seting.
midi clock can be reason why some note stucking or don't playing.
midi clock can be reason why you have clicking sound in your audio while master keyboard is on - no metter which OS you use!
so, if you have roland a33 or similar put them in the sea or in the deep river
no, no, no....... wait!!!
a33 is great but you must set midi clock to external - to avoid clicking sound, stucking midi notes....
this is very important tip

Another related tip: Some keyboards (ie: Kawai K5000) send active sensing which is continuous midi data! You can filter this out at the midi interface, or using a midi filter module in your sequencer - this can also help getting more reliable midi clock!

Be sure only ONE device is sending MIDI clock in your system! If you have a sequencer, generally only the SEQUENCER should be sending!