Why in the example 8 they can have more boundary conditions than equations?. I want to do something similar; solve a system of two equations with 4 boundary conditions, but matlab only let me put 2 boundary conditions.
Tim: I had the same ghost image problem; I fixed it by adding 'set(gcf, 'Renderer', 'zbuffer') around line 18 (after 'set(gca, 'nextplot' ...). I also changed the background color to white because the default was grey by using 'set(gcf, 'Color', [1 1 1])'. Hope that helps.