Thank you Sharkus for confirming some of the things I found when updating the driver. And I agree, unless the person is comfortable with database tools, they shouldn't do the delete.
What you can try in calibre is:
- Change the shelf column to a different column. If you have a text column with very few values it it, that would be good. You could add a custom column temporarily and use that.
- Plug the device in and let calibre do a sync. This should remove all the shelves that were setup before. If you have books on the device that are not in the calibre library, shelves they are on will not be affected.
- Disconnect the device
- Delete any other shelves still on the device that you don't want.
- Do a WiFi sync. Or stop calibre, reconnect and use the desktop app to do the sync.
- Change your calibre driver settings back. On the next connect, the shelves you want should be created.
If that doesn't work, we'll have to do some debugging. Also, if you are on the 2.2.x firmware, make sure you are on the lastest calibre. If you don't have it, wait for today's release. There is a nice addition to the driver for 2.2.x