Well, erm, haven't thought about that yet, but this Guard is a Standard-Model with a Standard-Texture, I haven't changed *anything* about it, I downoaded the demo and tried it the way it was. When I tried to make a model myself, I didn't use any material - not even a skin, just a monochrome Polygon mesh - and the error still occours. How is that possible....?
I've uploaded another picture, this time it shows my own model:



It was created using several different programs, and some of them ("Wings 3D" for example) already SHOW IT THAT WAY!!!! You may look right through the solid model. I marked the spots red in order to show you what I mean. If this would only happen with the models I've created myself I would say "well, a noob sometimes makes mistakes..." - but the Guard.mdl is a standard-model and if it had some sort of mistake someone would have noticed already, right?

Is it possible that this error is actually an error that doesn't have to do anything with 3DGS but with GXL properties or something that way? I'm using Windows Vista, Service Pack 1, if that does matter in any way...