Yup, DennisG. Noticed that. Just be aware this won't work with all templates included by Apple since some use different methods of doing the same thing, locked or unlocked.
Regarding the locked/unlocked, it's probably because of the change from LTR to the European paper sizes, or vice versa. I noticed someone else had missed a few of the lock/unlock things on their professional templates as well.
Templates are more complicated than the Keynote themes when it comes to their creation. Numerous paper formats, two distinct sets of sizes, a huge variety of layouts and placements. With keynote it's just a slide size and twelve generic master slides and you are pretty much done. With templates, expect mistakes due to the complexity.
(And I had pressed 'reply' to the original question. No idea why it considered it a reply to geepee's last post and indented it. It's these new forums and their odd behavior)