http://bugs.winehq.org/show_bug.cgi?id=9659
--- Comment #31 from Stefan Dösinger stefandoesinger@gmx.at 2007-11-24 10:54:59 --- Are you using GLSL or ARB shaders? I spotted a compiler bug on MacOS I could not reproduce in a test app in the code sequence that modifies the Z coordinate. This bug caused the skybox to appear in front of most objects.