that ridge is being formed because you have two horizontal edges close together forming a crease. grab a screen shot before smoothing so I can see whats going on.

so do what dave says and add another edge in the middle and then using my excellent steady handed paint over you can pull the center verts away along the surface normals to remove the pinching.

cheers

I have attached a non-pulsey version of my shaky paint over that hopefully makes more sense. lol