Problems with rendering materials.

Hello all!

I am having issues placing my material on the models so that it renders properly. As you can see on the attached pictures some of it comes out just fine, but some is "cubed". When i move the camera around various faces of the object alternately become normal or "cubed". I apologize if I am unable to use the proper terminology for this, but perhaps someone knows what the problem could be. Many thanks to all!