I had the same issue, with 3 Untitled CDs showing up for weeks. None of these worked for me, until I stumbled onto a solution accidentally.
1. Option click/double click on the icon in "Favorites" until it opens in a new window with "Untitled CD __.fpbf" as the name
2. Now control-option-click the icon and drag it to the desktop while holding the mouse down (2 keys depressed)
3. When it's on the desktop, press Command and the disappearing cloud shows up (3 keys depressed)
4. Let go of the mouse and it finally goes away.
I have no idea what causes this. I rarely burn CDs, but after the last one, I had 3 of these constantly showing up in my Finder--very annoying.