I thought I was having issues with the search function but I can't seem to replicate it so maybe I was the one fucking it up.

However the runes section in the AH is always empty?

That's something that needs changing. The word "Rune" doesn't exist in the database, but there is still a tab for it. I believe it's on the to-do list. All items which are tradeable and in the database are searchable. Even things that haven't been released for whatever the reason may be.