phe

I mean the setting in System > Graphics, on the right: FLAT TERRAIN SHADOWS with options ON and OFF

This might help: http://forums.eagle.ru/showthread.php?t=147980

I would also like to know if setting the "Flat Terrain Shadows" to ON actually enables something visually or is reducing the graphics quality of terrain shadows.

When I'm in LAlt+C mode in the cockpit and hover over a switch/button with the mouse cursor and it's tooltip is displayed, when I then press LAlt+C again to switch off the mouse look mode, the tooltip will still be displayed all the time until I press LAlt+C again (except when I leave the mouse excactly at the same X/Y position for as long as it would take to display a tooltip I believe - which would be impossible to do with TrackIR I assume). This was in the Ka-50 if that matters.