I'm getting a similar result when setting up new users with a custom security role. Prior to the update, when I would add a custom security roles users would be able to create new knowledge base articles and view articles already posted. Since the update, when I add a new user and add the custom secuity role, they do not have the permissions to add knowledge bases articles or view existing articles. As a work around, if the user is logged into CRM and attempts to access a published article they'll received access denied, using a security role that worked prior to the upgrade. If I remove the custom security role, add system administrator, have them try opening a knowledge base article, which works at that point, then remove system administrator, leaving them with the custom security role, the one they had in the beggining, it works...
adding and deleting the system administrator role while the user is in CRM shouldn't resolve the issue, but for some reason it does.
Any ideas?