Upgrading to 4.3.22 from 4.3.20 produced a change in how my Shared Folder is displayed. It is now listed in Windows Explorer with a tiny red "x" in the lower right of the network drive icon, followed by the text:
Disconnected Network Drive (E:)
In 4.3.20 (and all previous releases that I can remember), the listing is a network drive icon with a tiny green status, and then:
My_Shared_Folder (\\vboxsrv) (E:)
I hasten to add that the shared folder still works. I can share files back and forth to the Host O/S. But the way it's displayed in the Guest O/S is disconcerting, not to mention a different reaction to >net use and so on.
Mark