In a SharePoint 2010 site, that was not created using the team site template, users can't see each other's notes.
To fix this
- Login to the Central Administration .
- Click on Manage Service Applications -> User Profile Service Application ->
- Click "Setup My Sites" under "My Site Settings"
- Scroll down to the "Security Trimming Options" section.
- Click "Show all links regardless of permission". This allows everyone to see each other's notes on all sites in the farm.
- You can also specify the site Url(s), for more control over who sees notes, tags, feeds & ratings .
- After clicking "Ok" I can see other people's notes.
