I'm on a Windows laptop, but this same issue appeared on my desktop as well. never was able to solve it.
but often when i go into a folder to look at files, i'll have duplicates of every single file but with a dot in front. like .ieatham.txt as a copy of ieatham.txt. every solution i've found online and here in the community suggests it's an OX problem. but apparently not always, as like i said before, i'm on a Windows machine.
i do go through on occasion and delete the errant files. but this is something no Dropbox user should have to go through.