"File>Synchronize" synchronises some files repeatedly

I use DT since about three years (Pro Office 2.1 now) I have around 10000 pdf’s, mainly 15-20 page journal articles. I have an elaborate systematic file system in Finder and synchronise to DT. I synchronize frequently, sometimes more times a day. I then replicate these files, and sometimes whole folders further to DT Folders. I read and annotate files in Preview, opening from DT or BookEnds, to which the files in Finder are linked as well.
Today I found a file that I have synchronized 2 years ago (Tools>history) into the dB and behaved nicely until 4 days ago, when DT has added a double duplicate 4 times, I did not manipulate (view or annotate) that file recently.
This happened a few month ago, I deleted the files from finder, synchronized, downloaded fresh files, to no avail. I then parked them somewhere outside the workflow and hoped for the best. I should have known better. At present it is a nuisance, but it could become worse.
Any ideas how to prevent this.
Thanks

I had this happen just a few weeks ago with approx 6 or 7 pdfs (journal articles). I deleted them from my drive, re-indexed the folder, re-downloaded the articles and then re-indexed again. That seems to have cleared it up, so I reasoned that those particular pdfs had, for one reason or another, become corrupted.

I note you’ve tried this and it didn’t work, but thought I would chime in to say you’re not alone.

David

Since database corruption and file corruption are both possible, there are some recommended actions to attempt that might resolve the issue:

  1. Tools > Verify and Repair
  2. Tools > Backup and Optimize
  3. Use Disk Utility, Onyx, or a similar utility to check permissions on your drive