Check these things on hu.wikipedia.org:
See [[Hévízi-tó TT]] (you can find it in recent changes if you're not accent-read), and check "Mi hivatkozik erre" ("who links here"). Nobody.
Now go to [[Magyarország természetvédelmi területei]] (in the recent changes as well), and look for the string "Hévízi-tó TT", and you'll see: the article contains link to the one before. However its link is "red" or "question marked". If you click on it (create a non-existing article) then you'll realise that it does exist, since the editor window contains the actual text.
If I would edit and save the second article I'm sure it'd heal (preview shows it healed) but I don't want to mess it up until someone check what the bug is.
Brion? See anything?
(The article can be fixed, naturally, but the bug should be instead. :-))