The JV1080, 1010 & 2080, as well as the XP60 and XP80, operate pretty much the same way, but it IS different from the Korg stuff... the terminology was what tripped me up.
I use an XP60 (which sound-engine wise IS the 1080) and a JV1010 (which sound-engine wise IS the 2080)...
Multitembral mode on Roland gear is called a performance, so the Roland must be in "Performance" mode to play multiple instruments.
It sounds like you are in "Patch" mode (there is also a Rhythm mode for just playing drums), which will only let you play one at a time.
On the 1080:
Once you have the 1080 in "Performance" mode, you can select instruments on channals 1-16, and the Roland will change the instruments on "Part" 1-16 accordingly. By default, channel/part 10 will be the drum part.
Set the 1080's "Performance Ctrl Channel" to channel 1.
In Sonar:
Now... import the Roland JV1080's Patch, Performance and Rhythm instrument definitions into Sonar via the Assign Instruments dialog and...
set the output channel for the 1080's Rhythm ins to channel 10...
set the output channel for the 1080's Performance ins to channel 1...
and set the rest of the channels to the 1080's Patch ins...
Close the dialog.
Now, you'll be able to turn on Sonar and the JV1080, select a 1080 Performance (there are several of these) on channel 1, select a rhythm part on channel 10, and select patches on channels 2-9 and 11-16.
I do this all the time and it works great...
Keep in mind that a "Layer" Performance in the 1080 is not what you want for this functionality, so select Performances that are "Single" Performances. This is defined via the "Key Mode" parameter on the JV1080 itself. Select the instruments for multitembral playback on any "Key Mode: Single" Performance.
Good luck... give it a few weeks to sink in and then you can start playing around with effects/chorus/reverb settings and sysex dumps to Sonar. You can do quite a bit with Sonar and the 1080.
- zevo
If you have any questions, post back.