Dragging scrollbar during Copy operation fails

Greetings Gurus, during a file copy/move operation and I'm dragging a scrollbar in a lister the scrollbar stops responding to being dragged after a few moments (the copy/move progress window can be minimized or inactive). When the copy operation completes everything works fine.

Are you using any script add-ins? Doss it still happen with them all disabled?

Does it happen with all file display columns except Name removed?

Is the copy command just the normal one, or something more exotic?