Thanks for the suggestions for saving our crummy inexperienced job we did on our chair rail. First of all, I used a coping saw and cut a really thin slice off of an extra peice of the chair rail and stuck it in the gap with some wood filler. Now it looks like the corner matches just fine. With a little caulking, as someone suggested, it's going to look just fine. Now I don't feel as if I'm going to throw up anymore!!!