Not sure if i understood you fully, provide an image or something to make this more clear. if you select an edge that isnt what you expected in smooth preview, but is looking like you want it to in normal preview, try finding one edge loop near the area that is "messing up" and bevel it, you will see the difference and the affection bevel has to this area. duplicate your mesh and go to mesh-smooth to see what actually happens when you press 3 (smooth preview)


if you get annoying creases, you might have too many edgeloops at one place, to get rid of this crease you'll have to delete some edges and if they are important i'd add more loops between the area where you have many edgeloops at one place and the edgeloops closest to them, that'll make the crease less creasy but an image would help to understand this