I'm sure there must be a solution to this problem, which ive had a couple of times before. In the picture you can see i've got a border edge running along the side of my model. This stands out alot when smoothed and rendered, and 'sucks' in and distorts some of the surrounding geometry. I've gone all along it making sure that its not a merging verts problem. I had a similar line elsewhere on my model when i attached two objects together from which id deleted faces. The solution then was to run edge loops across it, but that doesnt work here either. Its come (Im sure) from how in some areas ive extruded faces, and in others ive switched to extruding edges. Has anyone got any ideas of what exactly the problem might be or any suggestions of how i could cure this?