Thank all of you for the helpful replies.
Disconnecting does solve the issue, the problem is that it keeps happening.
The reader worked correctly until today. I installed Koreader and it worked like a charm.
Today I connected the reader to
ADE 3.0 to remove a borrowed ebook and added a new one (my town has a nice virtual library). I used the occasion to sync the reader with Kobo Desktop and it asked me if wanted to sync SD as well.
When I disconnected the reader, the library was gone. Rebooting fixed the issue, but the device didn't connect with Calibre anymore. Kobo desktop saw the device but couldn't sync it.
Apart this, all books worked correctly both with nickel and ADE
except the one I transferred over with ADE (the authorization was still active and ADE detected the Kobo correctly). Opening that ebook caused the Kobo to freeze both with nickel and koreader.
At this point I'm not sure if the issue is caused by:
- ADE
- Syncing the Kobo
with the SD
- Koreader conflicting with any of the above (which would be a problem, since I need the pdf manager)
Is there any known bug about this?