Font Activation simply doesn't work

I thought I'd try out the new Font Activation feature however it doesn't seem to work. Here's what I tried:

I created a new Pages document, typed some random text, changed the font to Comic Sans and saved and closed the document.

Then in Font Book I switched off Comic Sans - highly recommended

I then opened my Pages document and had a warning that the font Comic Sans was missing. So, no automatic font activation then...

I'd be grateful if others could try the above procedure and confirm whether it works or not for you.

Thanks,

Graham

P.S. The problem can be replicated with TextEdit too...