I have a little more information. Firstly, I was confused why I was getting the "Out Of Sync" message on the Andoird client. This is a "backup" or "read-only" share, so surely it should know nothing of the other clients syncing with it - how can it go "out of sync" with nothing? I then found that this message appeared if a file within the directory was deleted whiles Sync was running. If I did a full Exit of the application, and then re-started it, this error would often clear on the Android client, and syncing would then sometimes continue. So, the 'fix' here appears to be - only open S