I find it funny too, when I'm playing around with morphs or expressions (especially the smiles, the part between the mouth/nose) that I notice the difference between view and render.  In constantly spot rendering (habit from when I started 3D), I always make sure I know what I'm getting before I hit that render button.  I even full render a small image at times just to be sure lol, I don't like spending hours rendering to find something wrong.

...wolfie