Annoying, infrequent pop-up errors in Explorer during drag-and-drop

This happens maybe once a week or so while moving files:

1. I left or right click and start to drag some file.
2. As I'm dragging it and BEFORE I let go of any mouse button a popup
dings saying "Error" and mentioning a directory such as
C:/Users/Harry Greer/Cookies.
3. The dialog has to be dismissed and the operation retried.

There are a few patterns:

1. It always seems to be a drag from a window near the right side of
the screen to a window further left, or from a window into its own
folder-tree display at its left. Left-to-right and vertical drags
never trigger this.
2. The named directory is always in my home directory and is one of
those odd-behaved shortcuts introduced in Windows Vista -- most
commonly, Application Data but sometimes Cookies or My Documents.
3. It's never the source or destination of my mouse drag. At most
the mouse may have passed over it without the held button being
released, so the system should not be attempting to move or
copy the file there even if it did.

--
Don't you fall into the trap
Republicans are full of crap.