Hatena Star's "Favorites" feature is little bit complicated thus please start by explaining it.
Hatena Star uses this Favorites feature to determine capability of one user's posting a comment to others.
For instance there are user A and user B. If user A adds stars on user B's blog entry, user B can posts a comment in one month. An opposite determination is done to check if user A can add a comment to user B.
This relationship is updated each time users add stars on others blog entries.
We reviewed the process of our service at first. Then we found a failure case and fixed it.
At same time we recalculate whole information of Stars to update information of Favorites. Please visit your Favorites to check.
Thank you for comments and reports on various places.