After all these years, Windows (XP) Internet Status ( Control Panel | Network Connections | Internet) has Sent and Received reversed from normal usage. [ Bob: The Windows 7 equivalent does get the directions correct. ]
From the point of view of the Internet, bytes Sent are of course Downloads. It all makes sense now:
To test this theory, I downloaded the latest Opera 10.50 Beta (12 MB) with the result:
Sent went from 1,470,582,553 to 1,484,554,805 (13,972,252 bytes).
Received went from 83,985,137 to 84,325,547 (340,410 bytes).
It is obvious which is the 12 MB download.