Folder import missing ebook.

[andyrauc]

Hi
I have a folder with all my books I had a second folder with more books. Over time my folders have become a bit of a mess so to solve the problem I renamed the Calibre library so that a new one would be created when I added books.
I then added books and browsed to the first folder and all the books were added.
I then did the same with a further two folders. I have the duplicate file plugin so a lot of books were listed as duplicated. i chose not to import them. After doing the import I clicked on a book then show in folder. The folder only contained the metadata and the cover but no ebook. I did a search for the book and it does exist in one of the folders i imported. So for some reason the import missed the book. I have found that this has happened a lot. Would anybody know why this is happening and how to solve it?