Comment 20 for bug 747682

@ Scott
While I can't speak for design or those implementing what you're asking for would seem to introduce some add. complexity for very little gain.
As it stands now the drop shadow is just a .png drawn on the desktop, not part of the panel. So having it disappear when lowered to 0 was obviously much simpler than what you'd like to see - (I think the 'trigger' to disable is @ 0.0050