Open the Library in grid view, with the Info panel open.
Click on the title or cover image of a book that is not the currently selected one.
Result: It opens the book (as expected), but it doesn’t also select that line as the currently selected book, which it should.
This is very annoying when working through tagging books. Suppose you have a book selected, which you've just been applying tags to. Now you click on some other book in your list to open it and see what it's like so you can decide how to tag it. Now you go back to the Library and click on the "add tag" link, thinking you’re adding a tag to the book you just opened, when you’re really tagging whatever other one happened to have been selected before. It should not have to be a two step process to select a book and open it.