I try to make an accompaniment for one jazz standard and I encountered one problem. I set the arpeggiator for bass and drums and then I started playing. The drums were playing correctly, but the bass stopped immediately after I started to play with my right hand (although I narrowed the bass range only to the two lowest octaves)
The bass only plays when I hold the chord or when I just hit the chord and do not play anything. I do not understand why it is stopping, I use similar setting for drums and they play correctly.

These might help:
http://www.motifator.com/index.php/forum/viewthread/461118/
http://www.motifator.com/index.php/forum/viewthread/455828/
http://www.motifator.com/index.php/forum/viewthread/445409/

Note Limit for the range of notes set to trigger/control the bass arp (which is probably a mono sound) is set improperly… you have not NOTE LIMITED the control region for the Bass… you only want to control the Bass with your left hand so set the ARP’s NOTE LIMIT accordingly. Not to be confused with the Note Limits that control the PART’s sound.

Press [EDIT]
Press the numbered button that corresponds to your BASS Part
Press [F1] VOICE
Press [SF1] VOICE - here you can set the PART NOTE LIMITs (this determines what pitches will sound)
Press [F2] ARP MAIN - here you can set the ARP NOTE LIMITs (this determines what keys will trigger/control the Bass ARP
the NOTE LIMIT parameter for the ARP control must be restricted to the region for left hand - the PART NOTE LIMIT is different (you may want to set that to full range) but the ARP NOTE LIMIT must be restricted to just the key range you want to use to control it. Make sense?