Fair enough Jimmy you may be one of those people that actually aren't suited to their harness was just making the point that a lot of people on this forum post about a problem they are having and people reply, get x product to fix. I'm sure most kite shops will have a demo harness... Try a whole heap find which one suits you... No one on this forum will be able to tell you.
So you're not a fat bastard and your technique is ok.
That leaves you with your harness is done up too tight.
Loosen it off a *little*. The harness will slide up momentarily then slide straight back down when you bring the kite back down. If it's too tight it will ride up over your ribs and wedge there.