LT says I have 27 books that I can't find in my catalogue

I'm doing a catalogue restructure and used power edit to delete all my books except the ones in my Read But Unowned collection. LT shows 591 books in that collection, but when I go to All Collections it shows 618 books. All my other collections are empty, and I have no inactive collections. Have I made an error, or is this a bug?

>1 Amberfly: At the bottom of https://www.librarything.com/profile/Amberfly/stats/collections there is an inverse option to see all books not in a specific collection. Maybe that will help you find them? Books aren't supposed to not have a collection, but I think sometimes things go weird.

>1 Amberfly: You have 27 books that aren't in any collection: https://www.librarything.com/catalog/Amberfly&special=collectionsinverse:5. You should be able to decide what to do with them from the link I gave here. Hope this helps!

>2 coprime: and >3 kristilabrie: Thank you! I have no idea how that happened and I really didn't want to comb through 600 entries by hand to find the discrepancies.