I just tried to clean up my Manage Your Kindle page by deleting the foreign language dictionaries and user guides that I don't need/use/want. It says that it has successfully deleted them, but they don't actually go away. I wonder if CS got tired of having to repopulate customers' Cloud with them so they made them permanent Books? I did not try to delete any other books as I want those, but I did successfully delete a couple of Personal Docs I no longer wanted in the Cloud.