For a while now I’ve been having a material issue, from back in 2.6x and still now in 2.71.
Solution:
Apply the modifiers, ya dunce.
Summary:
3D viewer shows correct materials, in-game does not.
Object with multi-materials only.
Materials in a list seem to offset or distort within the list.
Elaboration:
The glitch seems to be related to material indexing (?), this is speculation, I really have no idea. But it seems to change when I add or remove more materials to an object, and assign them to faces. Nothing changes until I actually assign the materials. The glitch LOOKS like either one material in the list for an object becomes invisible (usually the first), or the materials become re-arranged, e.g: Gold for car body, glass for windows and screens, black for darker surfaces - becomes - Car body becomes invisible, glass becomes black, and black becomes glass. And finally, the 3D viewer shows correct yet game engine does not.
Image:
Blendfile - .blend