Here's a screen shot that may do a better job of demonstrating the problem than I can do with words alone:

If I select and try to drag and drop from the left pane to the right pane, if the mouse cursor is hovering over the text of a file name, a black circle and bar show on the screen indicating that it will not be able to perform the copy.
If I try the same drag and drop but locate the mouse cursor so it does not hover over a file name, there is no black circle and bar, and the copy functions as expected.
I'm not sure if this behavior is intended or if is a big, so I erred on the side of caution and wanted to post about it.
Thanks much,
BK