This might help...assuming that the geometry is ok.
select the object, then under normals menu, select soften edge. Then with the object still selected, open up the chanel editor. You will see the softedge in your history with an option to change the angle. Try an angle of 30 to begin with and if that doesn't work then just try different angles to see if you can find one that works. If not, then it's probably a problem with your geometry. If so, maybe do a clean up.
Don't be satisfied with what you can do but rather strive to do the things you can't do!