Lost Tree Shadows on Terrain -How do I remove a Lightmap?

Hi everyone,

I found other users here in the forums wih the same problem, but their solutions do not work for me.

I use Unity 4 (free).

First I baked a Lightmap on my terrain, but it did not work out as i planned. Now I try to remove the lightmap, which I did by pressing "Clear" in the Lightmap settings and unchecking the Box in the realtime window saying "use Lightmap"

The Lightmap dissappears, and as long as I am in the edit-mode, all real time shadows of my trees are visible.

NOW: As soon as I press Play to start the runtime, all TREE shadows on the terrain are gone. My real time shadows on my meshes work, they cast and reveive. But the trees on my terrain wont cast any shadows - not on my terrain and not on my meshes. When I return to the edit mode, all shadows remain gone like in the runtime.

I tried different things like deleting the light map - file, setting it to 0 distance, putting it on index 255. . ... things that worked for others but not for me. My terrain is supposed to cast shadows (Checkbox in Terrain settings)

I need my realtime shadows back!! Thx for your help!

(EDIT) Hey there, it appears that my terrain can receive shadows now, but the trees don't cast shadows any more. SO the problem lies with the trees! I changed the desrition of my problem above....