Issue #33 was an bug that would cause the EDMCOverlay.exe window to be hidden and no overlay graphics to appear. If the overlay was started up before another program rendered a new window or dialog, the overlay would no longer be a "top level" window and think the game was out of focus and switch off rendering.
The fix for this now means that EDMCOverlay now makes sure that it is the top-most window when elite is in focus.