I'm having a similar issue, and I'm pretty sure it's Sync (version 1.3 for Windows) related. I have several folders set up where my computer is the only one with read/write access and everyone else is read only. I have two files that had future modified dates. I changed the dates to sometime in the recent past and Sync recognizes them as modified and continues to see them as updated every 10 seconds or so. When I look at these files' properties again after that, the modified date is now 1958. So I move the files out of my shared folder, modify the dates again, check the dates afterwards and they are exactly as I put them. I now look at the shared folder, and these files are there as .!sync files, 0 bytes and Sync is not downloading them from anyone. They are just there. So I delete the .!sync files, and move the files with the corrected dates back into the sync folder. A few seconds later Sync sees the new files, adds them, and modifies the modified date back to 1958 within these files. I have tried deleting the shared folder in sync, delete the .syncid file and re-share but the same thing keeps happening. I cannot delete the files that are already shared since my Sync doesn't have the originals (unmodified future date) anymore, and putting these back in with a fixed date throws Sync into an endless loop informing me that the files have been updated. I do not know how to resolve this at this time short of creating a new shared folder and starting over entirely.