http://bugs.winehq.org/show_bug.cgi?id=14018
--- Comment #2 from Athrun samurai_no_densetsu@yahoo.es 2008-06-25 12:43:14 --- I have just tested, that demo works fine on a clean .wine directory, so I tested the previous install on a clean .wine too and worked fine. So looking for an answer I have found that the disappearing terrain behavior only happen when the registry key OffscreenRenderingMode is set to fbo or pbuffer. If the OffscreenRenderingMode is set to the default key backbuffer the game works fine.
So its only an issue when using fbo or pbuffer.