DAE ShadedMaterial update issue

Hi,

I'm currently working with REV 632 of GW. Applying a ShadedMaterial to my DAE is not the Problem but it seems there are some issues when updating the Material.
The Material updates when i rotate my PointLight3D around my DAE but when i simply rotate my DAE there are no visible changes.
I also tried to rotate my Camera together with the light source around the model. The Material seems to update but still the main parts of the back remain black and the front part remains white.

Any Ideas?

Christoph