I sync my 1Password data files via Dropbox between Windows and Mac. It works fine, however, the dropdown menu on my Windows browser shows two entries for each site I have a password for. Only the second entry listed works as the first seems to be invalid. I use Firefox on both Windows and Mac. The Firefox browser on Mac works fine with only one entry for each site/password. I have insured all plug-ins are updated as well as the browser and 1Password.