I have Dropbox on my Windows PC, Android phone, Android tablet, and my Kobo ereader has Dropbox built in. They have all worked together to sync all this year with no problems. Today (11/3) I added 6 ebooks to Dropbox in Windows but they do not show up on any of my 3 other devices. Also today, I added an ebook to my Dropbox app on my tablet and it showed up right away on all the other devices, Windows included. Why is Windows not syncing things added to it with the other devices? Yet reflects items added to the other devices. I'm stumped.