Originally Posted by cryzed
I doubt that that is the Collections Manager's fault, but you can remove all your collections from the context menu and choosing "Delete all collections".
On an unrelated note: ixtab, do you know of a way to create nested collections from an import from Calibre? Currently I have a custom column called "Kindle Collection" for example with the value "Books, Fantasy, The Hollows" -- how would I go about modifying this value so that Collections Manager would automatically create a nested collection from that while importing? E.g. "Books/Fantasy/The Hollows"?
Easy: it's not supported. It would require significant changes to the logic, and it would also require some sort of naming convention that everybody would have to stick to. And last but not least: calibre doesn't support nesting anyway, so I think that calibre interprets that string as the book being part of 3 collections.
I'm afraid that you'll either have to resort to the "create collections from file system" option (which does support nesting), or create the hierarchy manually.