Chain of events:
Empty Recycle Bin silently fails. Tried it repeatedly.
Selected ranges of items in Recycle Bin and deleted them (some didn't work), narrowing down until only one item was left: a folder called Container.
Attempting to delete Container, restore it, or Empty Recycle Bin all silently fail: nothing happens, no error message.
Logging in as Administrator, that user sees a different recycle bin, that doesn't contain Container.
How to delete this folder from the Recycle bin without destabilising the system?
(On Windows Vista.)
