When I download anything with a folder, the contents are hidden. For example; I've downloaded several different things, one book in PDF format, a movie and some music (All legally) and the folder contents is just not there. It says it's there, when I search in finder I can find the files, and when I open enclosing folder, it opens the folder but it's invisible. I clicked compress just to see what would happen, and they show up. Clicking burn also does it. I had some folder actions on my downloads folder and recently removed them. I don't know if that would have anything to do with it, but the actions never messed with the contents of folders, only files in the downloads folder.