This problem pops up around once a fortnight sometimes it goes away if i close the program and reopen it, sometimes it takes a complete restart to clear it up.
The same thing happens to me too. Its not a big deal. If you want to restore the headings after they become all werid, just acess the Apple Store and go back to your library. This should fix it, though not permanently.
Same thing happened to me in iTunes yesterday; just closed the program and re-opened and it was fine and havent seen it since. I am using shapeshifter if that makes any difference.