I see similar behavior: files that I deleted on my laptop, while BTSync has no connection to BTSync on my NAS (because client's office network firewall prohibits non-80/443 connections), won't be sync-deleted on the NAS when the connection is re-established while at home. I also see loads of ".!Sync" files on my laptop of "incomplete" file downloads, while I have setup the sync connection to be readonly from laptop to NAS! Why is BTSync on my laptop downloading files from the NAS when the connection is readonly? This is a backup scenario where I want files on my laptop mirrorred to a backup location on my NAS. Another funny thing: files on my NAS (that have been synced by BTSync from my laptop) cannot be deleted through the Windows Explorer: "You require permission from Everyone to make changes to this folder"...