To see this, open a drawing window and a command window.
In the drawing (initially not empty), select an object (Alt-click).
Switch to the command window. Delete all drawing objects, e.g.
DELETE FROM [Drawing Table]
In the drawing window, the selection remains visible, even though there are now no objects.
This weekend's build should fix that.
A follow up - the fix ended up not making it to 126.96.36.199 / 7, but it is going to be in 8 (we already merged it, there was a minor hold-off).