The moderator of a blog can create, edit and delet blog entries. In the acces tab, user without administrative rights can be named moderator. If such a moderator edits an entry of another user and saves it as draft, the blog entry disappears from the list of entries and won't appear again until the changes are published.
This behaviour is not expected and not correct, as any other changes made to an entry are readily accepted, including deleting a post from another user.
--> saving changes to another users' blog entry as draft should not remove entry from entry list