I have One Note notebook located on shared folder. When I edit it on one computer, other one does not see changes even if I close and open it again. The only way I have found to resolve this issue temporary: download notebook from shared folder to my computer. After it all changes are visible until next change from another computer.
Previously asked http://answers.microsoft.com/en-us/office/forum/office_2013_release-onenote/one-note-2013-does-not-sync-from-shared-network/155f037f-625b-4e77-9d76-87170c8a05f6