I had the same Issue, but in my case i'm on the way to an answer. On 1 PC (Win7) the "Chronik" (German Version) listed the fiel as removed from a peer, but the file remains in the directory, and provably on the next Filesystem-Scan it was re-copied to the other peers. I discovered that the reappearing file was set to read-only. After resetting the Attribute the file was deletet as expected. The Cause of the read-only Attribute is still to investigated. Unfortunately in the Debog-Log was an Entry that the File was removed from the Peer, but the Failure of the real deleting was not listed.