-Layer and Culling Mask are the same.
-Terrain Settings 'Cast Shadows' is checked.
-Lightmap Shadow Distance and Quality Settings Shadow Distance are both set to a high distance.
It seems like some kind of node is being attached to previously lightmapped objects that ignores cast shadows after baking, even if the lightmaps are cleared.
You can see the real-time shadows again if you change the "Lightmap Index" value to 255 in the Atlas
If the object has an index in the Lightmapping Atlas then the real-time shadows are not visible for that object. But you should assign the old value again if you need to calculate the lightmap again (or clear and bake).
answered Nov 18 '11 at 11:26 PM