Relates to: T25882
Turning on the VBOs option in the preferences causes the texture to get messed up on the faces with the second multiple material assigned. Once you enable VBOs you may have to tab in and out of edit mode to see the issue.
To recreate the bug:
Unwrap the object, and open an image texture for the UV.
Add the same image as a texture on the material with UV coordinates.
Add a material slot so the object has 2 (multiple) materials.
Change the material color for one of the materials so you can see the difference without textures.
Assign one face to the second material.
Then enable VBOs option in the preferences.
The texture on the second material will get all messed up when the Textured Solid display option is selected and the 3dview is Solid Shaded.
Same thing happens with VBOs enabled when you go to texture paint mode, and use Multitexture or Texture Face display setting, and have textured shading for the 3dview turned on.
2.56 r34076 Official 2.56 release
2.56.0 r34454
2.56.0 r34481
Windows 7 64bit
Nvidia GTX 460