Updating Indexed Items

It does not look like the files in an index Dropbox folder are updating. I tried a number of times, but I see all sorts of discrepancies between what I have in the Dropbox folder and in the Indexed group in DTPO. To update the files I go to File > Update Indexed Items. What might be the issue? And what else should I try that would work better?

Please start a Support Ticket and include screencaps of the indexed folder in the Finder and the indexed group in DEVONthink.