Guess what I've just noticed
and apologies if you all knew this already, it's only taken me 10 years. Because I don't have wings at the moment and the journal entry notifications aren't working, I've been following a book I released by clicking on the image at the top of my profile to see if it had been caught yet. What I didn't know is that when someone else journals it, it disappears off your top 6. I didn't need to click on it every day, just wait until it had gone. This of course doesn't help when you have a lot of books and it's no longer top 6 but it's useful to know.
It came in with one of the site upgrades along the way :-) It's as though books can only appear on one person's profile page at a time, even though someone else journalling it doesn't stop it being one of the last 6 books you journalled/released/acted upon/whatever yourself, which is what the profile book covers are! Seems like an inconsistency to me!