I have having a similar problem with the difference being I'm trying to share and sync a note, not a notebook. Specifically, I'm trying to share a grocery list note with my wife. I'm a premium member. She's a free member. I shared the grocery list note with her. She can see it, but changes done on either side aren't synced. I've removed the sharing and deleted the note from her account, and then reset up sharing. That didn't fix anything as I hoped it would. It seems clear this should be supported per the following Sharing Notes article on the Developer page: http://dev.evernote.com/doc/articl