Umm.. can you explain what happens when you try to play single notes? Do you get automagic chords played? Or does it evaporate and nothing happens? Do you have it recording to a muted track or something?

(And I'm not sure what you mean when you say "single notes" and then add "base *and* guitar" - does that mean you're trying to trigger both voices with one key press, or that you have the same problem wihether it's bass or guitar?

In song mode if I have "arp on/off" button in the on selection I can record bass arpeggios

guitar arpeggios

and when I try to record the same voices w/arp on/off in the off selection,and try to play the bass or guitar parts in a single note progression the the keys either have no sound or low velocity.I hope this explains my problem better Thanks