I'll try to describe my Dropbox sync problem simply, it's not easy to do!

Four locations in question for my main.sndb file.

(1) "Laptop data file", i.e. database file that I load into IQ and edit - C:\Users\Jim\Documents\infoqube\main.sndb
(2) "Laptop sync file", i.e. file copied into sync folder when there is a "data change" - C:\Users\Jim\Dropbox\infoqube\sync\main.sndb
(3) "Desktop sync file", (a) file synced by Dropbox from laptop to desktop, (b) IQ detects that it has a Last Edit date later than the Desktop Data file, and (c) prompts me to overwrite the Desktop Data file with the Desktop Sync File - C:\Users\jimsp\Dropbox\infoqube\sync\main.sndb
(4) "Desktop data file", database file that I load into IQ and edit - E:\data\jsw\documents\docs\infoqube\main\main.sndb

So there are several steps for data changes to travel successfully from the Laptop Data File to the Desktop Data File.  when I want to work with this file on my Desktop after working with it on my Laptop, I need to make sure that all of these steps have been completed successfully.  If they have not been completed successfully, and I then make a data change to the Desktop Data File - the Desktop Data File will be copied over the Desktop Sync Folder, overwriting any changes that were made on the laptop.  This file, without the lost Laptop changes, are then synced back to the Laptop Sync Folder, overwriting the Laptop changes in that file.  And finally, IQ on the Laptop might prompt me to overwrite the Laptop Data File with file from the Laptop Sync Folder, containing the changes I made on the desktop.  The changes I made previously on the Laptop are lost and I may be none the wiser.

So lately I come to my Desktop, and I see an Overwrite prompt.  I click to Overwrite the Desktop Data File with the Desktop Sync File.  Very soon later, I often get a second Overwrite prompt, with a newer Last Edit date.  Once I again I click to do the Overwrite.  What I am discovering is that even after these two Overwrites, the Desktop Data File still does not have the last change I last made on the laptop.

I checked the Last Edit times on all four files.  (I copied the sndb files out of the sync folders and opened them from another location.)

So here are the Last Edit times what I see right now, displayed using File > Properties:

Laptop Data File - 14:08:21 UTC
Laptop Sync File - 14:07:35 UTC
Desktop Sync File - 14:07:35 UTC
Desktop Data File - 14:07:35 UTC

Now I can see the problem.  For some unknown reason, even though IQ on the Laptop detected an edit at 14:08:21, presumably a "data change", it did not copy the revised sndb file over the Laptop Sync File.  Therefore Dropbox never uploaded it to the cloud, never synced it to the Desktop Sync folder, and never prompted me to overwrite with the Desktop Data File with that file.  

To discover where the problem lay, I had to load four different files and check the Last Edit time with File > Properties.  I think that one thing that might help is if IQ would write a small text file to the Sync folder with the Last Edit information for each database.  Such a small text file should be synced almost instantaneously.  Maybe it could be a single text fie containing the Last Edit info for all computers from which that sndb file is opened and edited.  Then I could open that text file and compare the Last Edit date/time for that database for all computers, and I could determine quickly where the four-step process failed.  Perhaps I could display the contents of such a file directly from IQ.