Those both sound like good ideas...I'm just not sure exactly where to check.

1) How do I ensure that my material is capable of receiving shadows?
2) How do I add thickness to my faces...and will that help?

Another dimension to the problem, is I have a ton of light penetrating to the interior of the ship and bouncing around in there, causing further problems.

I'm getting the impression that the light is illuminating one side of the face, yet somehow both sides are being lit and the opposite side is transmitting light through. Does this help anyone come up with any ideas?

I've checked the normals and they all point outwards...towards the light.

-Brian