Are you in Performance mode?
Are you trying to edit a ROM performance?
Have you a manual for the JV-2080?
The 2080 should be easier to use than the 1080!
I suggest you pick a user performance,
and set each part to it's own MIDI channel.
The ROM performances from Roland tend to layer patches together, and normal they use MIDI channel 1. (or at least they do on my JV-880). This limits you if you wish to use that performance, as you've either got to use MIDI channel 1, or save it in a user performane and edit it to you requirements.
_________________________
The Sonic Energy Authority - a sound investment