I'd like to clarify a few of Mike's points for everyone...

1. The whole point of the RIDs:

If you copy a playlist from one device to another, how does it know if the song is already on the destination player or not?

Ideally, you would want to be able to copy a playlist from the Empeg to the Karma so that if a given tune was already on the Karma, it would only copy the playlist entry. But if the tune wasn't already on the Karma, then it would copy both the tune and the playlist entry.

How does it know if the tune is on there? That's the RID. It's calculated purely based on the audio data in the file. It's a unique ID number that tells one tune from the next without having to do a time-consuming file comparison.

2. The reason the RIDs sometimes need to be recomputed:

Because the Empeg, Emplode, and the Rio Central don't calculate them. It's a new thing they invented with the Karma. I *think* that RMM calculates them when you send tunes to the Karma, and I'm sure that the recent releases of Jemplode calculate them when sending to all three devices. It's only when you're dealing with tunes ripped on the Central, or tunes uploaded to any device with Emplode, that it becomes an issue.

3. What I did with this:

I have all the same tunes on my Central, my Empeg, and my PC's hard disk. I have a subset of those tunes on the Karma. But I still want all my custom playlists to be the same on all the devices.

Before, I had to copy tunes to the devices, then painstakingly hand-create the custom playlists on each device.

Last night, I did this:

Made sure that the new Jemplode.jar, riorid.jar, and riobackup.jar were all in the same folder on the hard disk.

Made sure my empeg (.130) had rids by doing this:
java -jar riorid.jar empeg 192.168.0.130 " " missing
(the " " is because I have no password on the empeg)

Made sure my Central (.4) had rids by doing this:
java -jar riorid.jar empeg 192.168.0.4 " " missing

Made a backup of all the playlists from the empeg, into a file named "backup.empeg" by doing this:
java -jar riobackup.jar empeg 192.168.0.130 "" backup backup.empeg

Removed all playlists from the Central in Emplode (or Jemplode would have worked). Did not remove the tunes, just the playlists.

Restored the empeg's playlists onto the Central by doing this:
java -jar riobackup.jar empeg 192.168.0.4 "" restore backup.empeg

After it was all done, the extensive playlist tree from the empeg is now working on the Central. It also works on the Rio Receiver that is slaved to the Central. All the menus seem to work, I can navigate to individual tree branches and play them, or play the top level playlist tree or whatever. It all seems to work.

Note that I could have also done this backup/restore operation with a much simpler copy/paste in Jemplode, but this way is faster because it doesn't need to individually-process each song as part of the copy/paste.

4. One issue with the Central:

If you do copy hierarchical playlists over to the Central, or create them on the Central using Jemplode, then you're stuck using Jemplode after that. Because Emplode assumes the Central has flat playlists, and you get Little Red Boo Boo Icons (tm) on all the hierarchical playlists.