Terrain building with errors

Hello, i move on to unity 3.3, and now i have a problem when i buid my scenes: the terrain details are not showing correctly, i alredy try with different terrain settings, and no mather witch value does the detail distance has, always i see them as it were set on 10. Also the rock details are all messed up (see pict), and i already made many changes (like changing the compression mode of the text, reimpoti the asset..etc).Maybe a bug, or maybe my nvidia gt220m....or windows 64.

Thank you