[brab]

It finally worked! The trick was slightly different:
- before quitting OF, shut down synchronization (doing it after changing the preference file does not work, it seems that the sync id comes back as soon as OF is started, and turning off sync then does not remove it).

- After shutting down sync and quitting OF, remove the sync id in the preference file

- Start everything again and sync in the order you suggested.

Thanks for the help!