When you search your knowledgebase as an end user, do your internal (private) articles show up in search? I noticed this for the first time today on my installation and am unsure if I caused it or if that's just how it is.
When the end user tries to click an internal article it does not let them view it, they are just sent back to the Knowledgebase page that lists all the categories.
Ideally the end user cannot see the internal articles at all, but if that's not how it works, no big deal.