In your first picture the vertex on the left is in front of the drawing plane. That's why the extrusion is twisted. As well as doing as sailor_ed suggests and using quad view, you might also try selecting the poly you want to extrude then choosing Selection>Move to Drawing Plane before doing the extrusion. Make sure you have the correct drawing plane active! The Carrara VM is not very intuitive. The Director's Camera view does not give a reliable way of placing vertices. It's essential to know which drawing plane you are working on and which constraints to use. Mark