I'm having this problem too. I didn't notice it occuring before installing 1.2.73, though am unsure when it first began. Deleting the file on the machine recieving the updated file seems to fix it, however it just happens again the next time the file is updated. Here's some pruned stuff from syng.log that may be relevant. There seems to be three copies of the file its having problems with in the same folder, in this case: Default.rdp, Deault.rdp.SyncOld, Default.rdp.SyncTemp. [2013-11-23 08:24:21.218] [SyncFolderNotify] Processing fs event[2013-11-23 08:24:21.218] [SyncFolderNotify] Event: FA_MODIFIED, File: Docs[2013-11-23 08:24:21.218] [SyncFolderNotify] Processing fs event[2013-11-23 08:24:21.218] [SyncFolderNotify] Event: FA_REMOVED, File: Default.rdp.SyncTemp[2013-11-23 08:24:21.218] Torrent \\?\G:\Docs\Documents\Default.rdp status:134 error:<NULL> meta:1 conns:0 io:0[2013-11-23 08:24:21.218] [OnNotifyFileChange] \\?\G:\Docs\Documents\Default.rdp.SyncTemp, source = NULL[2013-11-23 08:24:21.264] TorrentFile: download using patch (diff:32768) Default.rdp[2013-11-23 08:24:21.452] Merge: processing have_pieces message[2013-11-23 08:24:21.452] State sync finished for folder \\?\G:\Docs\Documents[2013-11-23 08:24:22.468] Going to connect to peer 192.168.69.144:14389 for file Default.rdp[2013-11-23 08:24:22.468] Torrent \\?\G:\Docs\Documents\Default.rdp status:137 error:<NULL> meta:1 conns:1 io:0[2013-11-23 08:24:22.624] Extension: ipv4:[*snip*] for '\\?\G:\Docs\Documents\Default.rdp'[2013-11-23 08:24:22.702] [SyncFolderNotify] Processing fs event[2013-11-23 08:24:22.702] [SyncFolderNotify] Event: FA_ADDED, File: Default.rdp.SyncTemp[2013-11-23 08:24:22.702] [OnNotifyFileChange] \\?\G:\Docs\Documents\Default.rdp.SyncTemp, source = NULL[2013-11-23 08:24:22.764] [SyncFolderNotify] Processing fs event[2013-11-23 08:24:22.764] [SyncFolderNotify] Event: FA_MODIFIED, File: Default.rdp.SyncTemp[2013-11-23 08:24:22.764] [OnNotifyFileChange] \\?\G:\Docs\Documents\Default.rdp.SyncTemp, source = NULL[2013-11-23 08:24:22.780] \\?\G:\Docs\Documents\Default.rdp: Piece 0 complete[2013-11-23 08:24:22.780] TorrentFile: failed to rename \\?\G:\Docs\Documents\Default.rdp into .SyncOld - 183[2013-11-23 08:24:22.780] Error: \\?\G:\Docs\Documents\Default.rdp - PostDownload: Cannot create a file when that file already exists.[2013-11-23 08:24:23.296] Torrent \\?\G:\Docs\Documents\Default.rdp status:152 error:PostDownload: Cannot create a file when that file already exists. meta:1 conns:0 io:0[2013-11-23 08:24:23.296] Error downloading file Default.rdp: PostDownload: Cannot create a file when that file already exists.[2013-11-23 08:24:23.296] Force unloading torrent \\?\G:\Docs\Documents\Default.rdp