When opening objects created by other programs, there can be mapping issues and you've just experienced it. This is not unique to Carrara - you can have this happen in any program and is more dependent on the authoring program than Carrara. 

Based on your screenshot, the domain assignments and the layer assignments are fighting each other. There is loop with the domain shader being assigned a layer shader that is assigned to the domain.

There are three fixes: 1) create 7 new shaders and assign them in the properties palette to the appropriate domain of the objects and then delete the layers in the layer palette, or 2) Kind of the same thing but you can create a new shader, one at a time, for the layers and then drag the layer from the layer palette into the new shader tree, thus deleting it from the original layer shader and then assigning the same "look" to the new shader. This will require assigning the domains to the new shaders in the Properties Palette as well. 3) delete or set to "None" the domain shaders.

The domain shader scheme is more efficient than the layers list scheme because multiple objects can "subscribe" to identical shaders. There is a way to do this also with Layers Lists but it's more work.

Mark