I just had the problem that I deleted a 150 MB file from this computer, on which it was initially also put in the shared folder, and it reappeared; it synced it back from the other peer. It should have propagated the delete. I had used that file before to do some experiments with kill -9 on btsync while it was running. I have been able to reproduce it twice. Btsync will have to be able to handle kill -9, because on Linux, that's how it will be shut down, since it's not a system service. And even then, computers can crash. Platform: both Linux 64 bit Version: 1.4 Steps Have a share on two peers. I added the write key of peer 1 to peer 2.Put a large file in peer 1While it is syncing and you see a partial !sync on peer 2, kill -9 btsync on peer 1.Start it again.Wait till it starts syncing (can be a while). You can also make another change on the folder, forcing a sync. Though, I don't know if that affects the result.wait till the sync is complete.Delete it from peer 1.It will reappear on peer 1. This is wrong. It should have been deleted on peer 2.