So I'm trying to make a lighting mod, which helped me notice that shadows (shadow maps) don't apply to certain meshes on the ground, specifically it appears to be grass and etc. that aren't receiving shadows.

You can see it here: http://i.imgur.com/GN4cD.jpg

Just to the left of the reticule, the grass is extremely brightly lit, obviously an error of some sort.

Obvious graphical bug, anyone?

This is hardcoded. Unlike Oblivion. the shadow maps do not render over the grass planes...

This has been fixed for the 1.5 patch. Shadows on grass is beautiful!