Material Shading Issue

I am in the process of moving the location of some project files due to a subversion cleanup and have been reloading all the connections for materials and textures. However, there is one model that remains flat shaded, no matter what material is applied.

The first image has a Specular material with the object's color texture, the second is the object with the default diffuse material, and the third image is a snapshot from the model preview window.

This model worked previously, but I have no idea what has changed.I have played with ambient color settings, and all of the inspector parameters for the mesh render. The scene has been lightmapped using Beast.

Any ideas? Thanks.