Same here. Unread posts has not worked since the upgrade.
Also, clicking the 'Unread Posts' option only shows unread posts to topics i already viewed (i think), not all unread posts accross all sections as it did before.
When clicking 'show all unread topics' i get :
Database Error
Please try again. If you come back to this error screen, report the error to an administrator.
Would be nice if i was given an option to 'report it to an administrator' as it is unclear where to do that (Support->Contact Us does not show a page or something for me).