If you open up the PIP (which now runs quite smoothly and has some pretty awesome features, I should add!) when you click-and-drag select in the main window, the box does not appear.
I should probably throw this in here as well: https://forums.uberent.com/threads/pte-pre-game-screen-suggestion.62155/
One of the AMD machines we have here does reproduce the issue, but I haven't been able to figure out why yet. It's a fairly new card with the latest drivers, and I have no idea what the cause is yet.
LOTS of cool new pre-game UI stuff. Armory: Replays: Settings: Lobby: EDIT: Also when you select a game in the lobby, the planets give more specific details on their size (namely radius)