I have some very odd result with a model of mine when experimenting with the BGE.
Attached to the post a Cube on a Plane, both unwrapped and assigned to a texture (that is packed) , and both using a same material+texture.
In Blender Render engine, there’s no problem, in the 3D View, there’s no problem.
Now in the Blender Game engine, in the 3D View there’s no problem, but now if i press P to activate the game engine :
In Single Texture display :
It actually looks like the viewport in Blender Render when it’s set to Multitexture display, though the shadow are less dark
In GLSL display :
It actually looks like the render in Blender Render, logically.
In Multitexture display :
It looks like what would happen if i had the material set to Shadeless.
But it is not set to Shadeless of course.
And now for even more bizarre , add a Subsurf modifier to that cube, do not apply the modifier and look what happens in Single Texture , GLSL and Multitexture display when pressing P.
When you’ll try Multitexture display, it will make the object simply invisible, until you either apply or remove the subsurf modifier.
Do you have a subsurf modifier on your model ?
It sounds to me like a bug, but i have extremely few experience of the BGE so maybe there’s some setting i didn’t noticed.
oddBGEmultitex.blend (106 KB)