I would like to suggest for SEO reasons, that if possible we could add parent category name to page title of questions.
E.g. a question titled "How to register"
its parent is "User" and its parent is "Registration"
The page title when viewed in google debug of that question would then be
"Registration - User - How to register"
Right now google is just picking up "How to register" which would not be good SEO wise..... than having the parent names in there.