I have seen photostream do this so many times, that I have stopped fighting it. Mine had been working, without any need to delete and re-install and reset my photostream finally for about 5-6 months. Then iOS 7 and iCloud 3.0 came out. My activity, shared folders are all up to date, my photostream on all iOS devices, synced, My Photostream, not synced since 9/24/13. Yep, just shy of 1 month now. I do not want to reset my photostream since it kills it on all devices. This would mean having to upload all the great pics I have now, and I'm just not in the mood to do this again. I have amazing pictures from a vacation several months ago, and this is something my son watches with music on AppleTV as a "night light" and he would be very upset if this was messed up again. I tried the one thing I hadn't done since the update, signing out and back in. It changed my photostream folder, and I think this may fix it, as iCloud has had registry errors for as long as I have been using it, PC wise anywise. I now have a few pictures syncing, and the shared folders are all there. One issue, my iCloud Photos Shortcut in the Favorites now says iCloud Photos is not enabled, even though it actually is. So there is yet another fix that I need. Anyway, here are some tips for you and others based on all the articles and trials and research I have done. I have never had it work for longer than say 3 months without me needing to do something, and on multiple computers, but, I always get it working for at least some time.
Tips from my many battles of iCloud Sync issues:
- Change your PhotoStream Destination Folder. If there is a registry error, this works
- Sign out and then Sign in on iCloud Control Panel. Rare this one will help, but it's a lot less drastic and no photo loss in the streams.
- Remove the iCloud Control Panel, restart your computer, reinstall iCloud control panel
- Remove the iCloud Control Panel, restart your computer, reinstall iCloud control panel and then (My least favorite option), Reset your photo stream
- click on icloud.com
- sign in using your apple id.(the one you use for icloud)
- once signed in click on your account name at the top of the page
- click advanced
- click reset photo stream and reset
- click your apple id in the upper left corner to return to the previous screen
- then click done(upper right)